8x10 film isn't a Ferrari. It's more like a diesel locomotive. Sure, it does one thing incredibly well (taking highly detailed photographs, or pulling insanely heavy loads). It's also massive, heavy, costly to own and operate, but more importantly, operates under constraints that make it unviable for the majority of use-cases.
Basically, you don't see 8x10 used more than prosumer cameras for the same reason you don't see trains dropping off freight at random stores and warehouses instead of trucks. Yeah you can flex your dick about the quality of 8x10 (which I'm almost entirely sure you yourself do not shoot), but it's meaningless if you're unable to even get the shot in the first place.