And you are denying the genocide that'll happen to those indigenous you propose are going to somehow take over the country.

1. The military. There is at least one greedy general out there that'll attack with our trillions worth of weapons research.
2. The nature of the indigenous communities. Okay, so you're giving them to "the Native Americans". I'm assuming that means all of them? Look at this infograph. They occupy less than 10% of USA's land and are spread out incredibly sparsely. If you just give it to one of them, well, that actually would solve a problem. But which one will you give it to? Is the Fox nation racially superior to the Sioux nation? If you give it to all them, they will have to effectively communicate, which is undercut by
3. The nature of the indigenous communities. Quite a bit of these communities have been recognized by the government as wards of the state and have been isolated by mutual consent. Now you're gonna entrust someone to hand them modern communications, weapons, tools, etc and not use these technologies to take power away from the indigenous instead. How exactly do you propose a power transfer to happen?