Thus Spake Zaraholden/GoldenAgeOfTheShogunate
The Dragon-Blooded Golden Age, aka the Shogunate
The hell it is. The Shogunate portrayed in the Aspect Books is subject to fairly regular collapses and overthrows of the central government, a crumbling infrastructure too complex for them to properly maintain, and constant border warfare with the Fair Folk that ends in defeat or stalemate far too often for anyone's comfort. Not to mention piss-poor relations with Heaven bordering on active obstructionism. The Dragon-Blooded hearken back to it as some kind of rose-tinted golden age because there were way more of them back then, and there was always a war going on to march off and be a hero in, in an ironic tragedy of the commons sort of way, plus they had greater access to cool magitech weapons like Dragon Armor. The Realm has proved itself to be a far more stable and widely prosperous governmental system than the Shogunate ever was, but nobody gets to call himself "Daimyo" so it rankles.
Quite a few things.
For starters, if Creation were not at all what it is, history might look quite different.
By which I mean, do you really want your entire culture to have a handful of Celestial gods acting as lynchpins that hold it together? Gods are gods, and always have been—they behave as well as they're forced to.
Putting it another way—Wyld-shaping technique was a premiere producer of the impossibilities the First Age ran on, but not the only one. You can also get, perhaps unsurprisingly, a lot of really powerful mojo from the most powerful denizens of Malfeas. Of course, no Solars means no Solar Circle sorcery, which means you have to bargain with the Unquestionable for their help keeping your infrastructure running.
You can probably identify some problems with making Creation's entire technological infrastructure, particularly its defense network, overly reliant on demons.
Moving on: Yes, you have Essence 7+ Sidereals to work with. Sidereals are chronically over-worked with top-priority business like 'make sure reality doesn't spontaneously melt.' This gets more and more true as they grow older; the Essence 7+ Sidereals have much more vital things they need to be doing than keeping the water purification plants in some city built on a toxic bog in the Southeast working at peak efficiency.
Okay, so now we're down to the Dragon-Blooded and here's where we start running into serious trouble. The Golem-Producing Wonder Factory uses square circles to calibrate its transmotic armor-sculpting armatures, which produces defensive automatons whose outer hull is both flexible and absolutely rigid, making them nimble and hardy fighters. Square circles break down after a while; their impossibility grinds against the mathematical certainties of Creation.
With the Solars gone, there's no reliable way to get more. So after a few years the Wonder Factory's automated production lines shut down. Okay, you're still left with your golem army, but every time the Fair Folk make a sortie against the region, a few of them get destroyed, so their numbers are dropping.
The Terrestrials examine the factory as best they're able. It's fucked; they can't fix it. But maybe they can make more golems by hand? They look into this, and yes, by hook and by crook, they can still hand-assemble these superlative battle golems... but it takes a skilled Terrestrial artisan and his assistants months and months to make a single one. That might slow the rate of loss, but a) you're tying up a technical expert and this is far from the only system experiencing difficulties and b) you're still losing them faster than you can make them.
So the Wonder Factory is closed and scrapped for spare parts. Eventually the golem army gets whittled down enough that it can't effectively protect the entire region; now individual local daimyos begin fighting one another about how to allocate the remaining golems, to best protect their holdings.
Things get worse, though. Every time the Fair Folk manage a breakthrough that eats away at the edges of Creation, that shrinks the world. There's nobody with Wyld-Shaping Technique to go get that land back, much less to actively expand the borders. Moreover, maintaining the land is hard—the Terrestrials are doing their best to uphold the left-over Solar edicts that make up the Order-Conferring Trade Pattern, but they're not up to actually understanding the system in its totality. When the raksha start punching holes in the pattern, the best they can do is make educated guesses about how to compensate and reroute trade networks. It doesn't always work properly, and so the stabilizing network that holds Creation's borders together slowly but steadily weakens.
A Skywolf-class aerial battle cruiser crashes during a battle with the 118th raksha air kraken division. Well, that's okay--that technology is fully within the understanding of the Shogunate, they can replace it, right? Well... yes, but. Gathering up the enormous amounts of required materials is hard, because most of the teleport gateways that were the apogee of Solar technology got broken in the Usurpation and nobody has been able to get any of them back up and running, much less build new ones. Others are being taken offline all the time because they are titanic Essence hogs and that energy could be better used on other things. So, getting the mountains of jade and other construction materials to the build site takes much longer than it would have in the First Age. Then designing the ship takes longer than it would have with Solars overseeing the project. Then building it takes much longer, especially because some of the automated factory-cathedrals are offline. What might have taken six months to roll out in the First Age takes ten years for the Shogunate to put together. This is assuming it's a priority project--it could easily take even longer. Remember, Dragon-Blooded crafting-speed multiplication Charms are awful.
Sidereals have decent speed-multipliers, but there are 100 Sidereals, many of them have zero Craft Charms, and how many priority projects like this do you think are going on across the entire world at once?
Shit! The Fair Folk forced a major breach in Mavais Prefecture! The entire city of Burnished Hope is lost-- and they're turning around its wave motion cannon to fire it into the heart of the South! Deploy the Soulbreaker Orb!
Well, whew. That worked. We recaptured the city and broke the raksha army. Anybody know how to make a replacement orb?
Crap.
What, we only have two left for this border sector? But that covers the territory of five different daimyos, who's going to have those remaining orbs stocked in their arsen... oh, they're going to war again.
Well, maybe the gods can help us get another one cobbled together. Dispatch a team of priest-diplomats.
Hey, they're back. What did Yu-Shan say?
They said what?
I'd have to summon a Neomah for that to even be anatomically possible.
In essence, the Shogunate would have probably stabilized at some point significantly above where we are now, but somewhat beneath the Autochthonians, if they'd managed to quit fighting themselves all the time. And if Heaven hadn't steadfastly refused to acknowledge the worldly authority of the Terrestrials. But "Heaven consistently tells the Shogunate to go fuck itself" and "Creation continually experiences cycles of widespread civil war and partial collapse of its bureaucratic and governmental infrastructure, often in the form of violent coups" are pretty much the defining features of the Shogunate.
So, the Shogunate would have been much more stable if it were not the Shogunate.
The Great Contagion did not come in and kick apart a healthy system that was stabilizing toward a sustainable state of equilibrium and renewal. The Shogunate was not something the Sidereals had under control. The Contagion just kicked the feet out from under a juggler who was already careening around, dropping balls like mad.
The interesting thing is that modern Dragon-Blooded look back to the Shogunate as kind of the 'golden age' of their people—that was the apex of their accomplishment, when Dragon Armor was standard kit and every direction had multiple aerial battle fleets and Creation was divided up among proud and mighty daimyos and their associated gentes. It was a grander age, and everywhere there was war and heroism!
The truth of the matter is that the Realm has proven itself a far more stable and effective institution than the Shogunate ever did. The Realm has not experienced periodic collapse of its central government. Peasants do not starve in the interior, nor are its lands wracked by constant war. It has successfully stabilized and maintained Creation, and at this point, the Realm has actually lasted longer than the Shogunate did (assuming that you reasonably don't count Lookshy).
But the peasants don't have Essence lighting and only a couple of rich eccentrics have robot servants and there isn't much dragon armor to go around. Boo.
Of course, now it's all crumbling with the Empress gone, but it also presents opportunity—the Realm is the first time since Merela that Creation has been unified under a single, strong ruler that wasn't constantly getting assassinated. The Realm is culturally accustomed to the idea of a long-lived, fairly unchallengeable ruler, as opposed to playing musical thrones. The Empress hobbled her own creation by designing it first with an eye toward her own security; the Realm's current boundaries represent the limits of her ability to control her territories in a totalitarian fashion. Her vacant throne presents a ready-made opportunity for someone else to pick up the most stable empire Creation has ever seen and to try to take it in a better, less selfish direction.
Or to just become Empress Mk II. Up to the stories you tell.