To be more accurate, smallpox killed somewhere between like 65-95% of the native american population after contact with Europeans. And, of course, many of their remaining descendants ended up concentrated into reservations.
So, I imagine if you were going to find native american cuisine restaurants, they'd be rare but typically in and around reservations.
The initial Spanish expeditions had herds of pigs with them, which transmitted a ton of diseases to the natives. A hundred years later when other Europeans came the cities were almost completely depopulated.
Many reservations are far from the original habitat of the people living in them, (see Trail of Tears) so the food materials for their original cuisine can't be found or grown
Guns, Germs, and Steel covers that in a brief but eye-opening way. When Hernando de Soto's crew first explored the Mississippi river in 1541 they wrote about all the people they found, but did not mention bison. A century later another set of Spanish explorers revisited the Mississippi and didn't record much at all about people, but commented on how prolific the bison were.
Worth noting GGS is incredibly poorly received in the anthropology community. If this was reddit most of the major history and anthro subs have a bot to debunk much of it.
Jarred Diamond, the author of GGS, is an eye doctor and bird expert. He isn’t a good source for this stuff.