True.
But unlike the Shogunate, Autochtonians do have semi-reliable access to Autobot's noetic archives for backup and retrieval, as well as examples of Primordial and First Age-level artifice.
Continuity of knowledge is a major boon for them, as is the fact that Alchemicals are Celestial-tier exalts, not Terrestrials.
Resource scarcity will hurt them, but is quite as likely to propel their tech tree towards efficiency.
That is, assuming they don't tick off a Divine Minister or two.
Yeah, see, this is bringing up a point which I believe I have reiterated repeatedly. I believe the entire canon set up for such things is stupid and burn it to trash, so any arguments based on "but canon says" can be discarded out of hand.
For example, Autochthon making Celestial Battle Armour? Dumb. Even if we charitably assume that WotL is not best used as kindling, Primordial manufacture should not resemble High First Age manufacture. Deliberative manufacture should be radically different from Autochtonic manufacture, and the armour which Autochton made the Exalted for the Incarnate Rebellion should only resemble High First Age armour in that... well, it's armour. And even then, Autochtonic armour may well be a living machine in its own right, inhabited by Autochtonic devas and hewn from magical materials which no longer exist in Creation, but which are common in Autochtonia.
Yes, I am saying that the crafts of the modern Demon Realm probably resembled the tools the Exalted used in the Incarnate Rebellion much more than they did the products of the High First Age, save when the veterans of the Rebellion deliberately aped the forms of the weapons of their youth.
And Alchemical manufacture should, likewise, be
notably different from Primordial Autochtonic manufacture. Can Alchemicals make devas about as easily as a human makes hair? No? Then they can't make a
lot of Autochtonic designs. Do Alchemicals have the People of Adamant to maintain their things? No? Then they are going to be confined to make things which the human mind can understand and work with using tools, rather than what inhuman earth-elves can use. Moreover, I will argue that Alchemicals simply cannot reach the peaks of Autochtonic craftsmanship - or Solar craftsmanship, for that matter - and that furthermore only Apostates can reach the peak of Alchemical genius, because they
need that mad transgressive blasphemous spark which enables Autocthon to do what he does. Most Alchemicals are not Apostates.
(Also, to be blunt Alchemicals
should be Terrestrial Exalted. They're potentially uncapped weaker Exalts who are fundamentally linked to pre-existing institutions. They have much more in common with Dragonblooded in the way they come about and their nature than the indestructible, reincarnating supermotes of the Celestials. But that's an argument for another day.)