The Indian Child Welfare Act pretty much guarantees that the segment of Native American children that live in absolute squalor, abuse and poverty are trapped there forever.
Just like the rest of society, there are dregs that are completely drug and alcohol addicted, child abusers, and certainly not fit to be parents of anybody or guardians of anything. Difference is, outside of Indian Reservations, CPS will take children out of that nightmare and give them a chance elsewhere. Not so with the Rez. Anybody who has ever really looked deep on-line at the near impossibility of adopting a child from a horrible situation on the reservation will never attempt to adopt a Native American child. For most all tribal authority, they feel it is better to have a Native child grow up in a completely abusive household in abject poverty because the chromosome donors are Native American, and for no other reason except they don't want them raised by a non-Native American.