Most of what people ate prior to modernization was really, really gross by the standards of modern restaurants because decisions were driven by limited ingredients and limited fuel. Most of what anyone ate at that time was boiled and, outside of regions with easy access to spices, unseasoned. When the rest of the world was developing modern food cultures, American Indians were being subjugated and, later, forcibly assimilated by American colonizers. The only really good recent food invention from American Indian cultures has been fry bread which, while delicious, lacks something in sophistication. There are lots of good indigenous mesoamerican dishes but they’ve been assimilated into mainstream Mexican cuisine. No one thinks of chili verde as a “Native American food.”
Look at Wikipedia’s article “Indigenous cuisine of the Americas”. How many of this dishes under the North America subheading would you actually want to eat? Probably fry bread, maybe fish or meat jerky or pemmican, and definitely maple taffy.
Everything else is either an ingredient or not very good. I have tried Jonnycakes and they are a step down from cornbread. My mom talks about occasionally eating “mush” (acorn porridge, which would have been called t’epna by her grandparents) as a kid. She describes it as “pretty bad.” Everyone in her family far preferred the version of the dish that was invented in the 20th century, “Frito mush,” which is pretty much Frito pie but with soggy Fritos.
What you’re left with is modern attempts to make new dishes featuring the ingredients pre-assimilation American Indians were using. Mitsitam in DC is doing this, and I like their food (or, at least, liked - I haven’t been there in years and reviewers say it’s gone down hill). It’s stuff like “Indian tacos”, “seared boar”, and “salmon chowder.” The only thing there any Indians I know would eat day-to-day is Indian tacos, and I think there are literally no ingredients in those which are native to America except maybe some of the spices in the seasoning (they are regular Tex-mex tacos, with ground beef and the packets of seasoning, but made on fry bread instead of tortillas). I think this is probably the right way to go about doing American Indian cuisine, but it’s just not going to be recognizable in the American eye as an ethnic cuisine in the way that Italian and Chinese cuisines are. Instead, it’s going to look like traditional ingredients prepared with modern American and occasionally modern Mexican cooking techniques. Without knowledge of the history, that seems like it’s “inauthentic” or “westernized”, but really it’s all we’ve got. Well, that and frybread.