In many places, good faith sales are respected. Say someone bought a TV that "fell off a truck", but then after a year sells it to another person insisting it was legitimately acquired. The second buyer could be a legitimate owner given the they purchased the TV in good faith. On a side note, even if you did legitimately purchase the TV why would you expect the manufacturer to buy it back from you after it was used?

Regarding the realities of the situation in Oklahoma: as of this ruling non-natives on native land outnumber natives more than 4:1. If the government aimed to take or redistribute private property I would expect major unrest as a consequence.

All land is stolen property, there are very few direct inheritance lines going back for more than a few hundred years. There are none that go back thousands.

To give an example from the german jurisdiction, if you buy a TV that fell off the truck, you are in posession of the TV but do not have ownership of it (however, you are not required to actually give the TV back, you can do what want with it).

If you sell that TV to a third party, ownership passes to that third party and the original owner looses all property rights on it. One of the few examples where ownership can pass from a party to another without the first party's consent (in neither express or requirement).

I imagine US law isn't totally different there.

It certainly makes sense for government/crown land to be given back to indigenous nations that hold title.

You could do the same thing I suggested albeit free for the Nation and the private landowner seller could be compensated by the government (which stole the land and resold it in the first place).