Ok so I have big issue with the amount of time passed in that I can't suspend my disbelief. I find it really damn stupid that nearly twenty thousand years have passed there is are grand radical changes to the setting and it still continues to be a generic fantastic version of Medieval Europe. It's way too damn big of a number for not nearly enough to have happened setting wise.

In the real world according the wikipedia the beginning of the medieval era was in the 5th century which began at 401 AD and if I did the math right the time between that and now is only 1615 years. 20 thousand years ago would place us in stone age where man was running around in skins being hunters & gatherers building huts and shit. 

The loss of magic (which honestly isn't that big of a deal since humans in the game since they could never wield it directly like a typical rpg mage, outside of being a dragoon which was the really big thing for humans and magic) and the war would actually accelerate technology, especially with war and the concept of a arms race, where you try to develop something to beat the enemy's thing and they counter with some other improvement and it continues. 

And what sticks out to me is the Queen Fury. You know the thing in the third or second disc that's part of the big story arc revealing more backstory and some development of the party? The pride of Tiberoa's navy, which I believe was mentioned as being a technological marvel of the nation which did not use any magic. That thing is basically is one of those civil war ironclads which is a steamship, but with silly battlements to make it look like a floating castle. So Endiness or Tiberoa at the very least already has pretty advanced tech to make a working large scale steam engine.

So in the millennia that followed before the war and the millennia during the war you're saying that the technological foundations that allowed for that steamboat to be made that there have been no advancements in like making that piece of technology accessible and better as well as supplanting it with something more advanced within  despite it almost being twenty thousand years since its first (at least ingame) appearance? 

Yeah, I just can't believe it and refuse to. Maybe with something smaller and under like a thousand years I could believe not much has happened, but the moment you toss something that absurdly big it just gets silly. Seriously in that span of time you could dig up the long dead remains of the party and put them in a museum exhibit of ancient peoples.

At leas the events of the game had the excuse of being possibly some sort of post-cataclysmic setting that got rebuilt given that during the human-wingly war magical nukes were being tossed around that not only scarred the earth but also messed with reality in those areas affected.