Its a horribly effective strategy.

Oh shit… I forgot to mention something in my OP

Tribes that did manage to survive and were given “land” somewhere in the USA were expected to pay property taxes on that land.

So a displaced people, who had lost everything, were expected to immediately set up profitable businesses to pay that bill. When they couldn’t pay the taxes they’d either had the land confiscated and were evicted from the land or they’d sell the land and become displaced again.