crafted gear shouldn't be the best because there's no good argument as to why crafted gear should come close to the kind of tech they were putting out before shit hit the fan
Interesting logical tack, but there are plenty of good counter-arguments.
Crafted gear may be fabricated in whole or in part from intact or refurbished components that were designed and manufactured before the fall of the pre-Underrail civilization.
Furthermore, the contemporary civilization of Underrail was never wholly severed from the technology of the past; there was no total descent into a Stone Age analogue. Continuity was never fully (or even mostly) obliterated. Well-heeled scientific organizations, though they may have changed their structure, fragmented, and/or degenerated, continued to advance the research of the megacorps for decades after mankind went underground—perhaps not as well or as quickly as could have been accomplished above ground, and yet the lore of the game makes it clear that the environment of Underrail, in and of itself, contributed in certain ways to the advancement of technology, both because of the unique biomes that evolved and also due to the demands and necessities of life below ground.
Did you forget about The Dude (LSD-themed mad scientist) and what he accomplished while living in Underrail? He may be included in Underrail mostly for comic relief and an acid trip-themed adventure within the game, but he is part of its lore.
In addition, the Oculus and various superhuman beings suggest that outside elements—space aliens and such, basically—may have added spice (and technology, etc.) that wasn't in the soup hundreds of years prior.
All of this is to say that you haven't thought this through enough. My main point is that the thread of the past wasn't wholly severed, that technological advancement didn't grind to a complete halt, and that in some ways it may have been augmented.