>Instead what happened is that, by creating the reservations and encouraging them to maintain their traditional lifestyles

Aside from simply not forcing them to integrate into mainsteam society, how did mainstream American society over the last 102 years encourage them to maintain traditional lifestyles?

Since the "Indian" Citizenship Act of 1924, every native American born in the US (on a reservation or not) has held US citizenship, free to move anywhere they want in the US just like any US citizen or lawful resident (who is not on probation after having been convicted of a crime). I am tempted to conclude that the main effect of the existence of reservations after 1924 has been to give native Americans the choice between integrating into American society with all the advantages any other immigrant would have (by moving off the reservation) and continuing to live in a jurisdiction administered by members of his or her own tribe (by chosing to stay on the reservation).

Actually the situation is a little more nuanced than that because Washington has disbursed money to the tribes every year, and some of that money goes to benefits (e.g., housing assistance, healthcare (via Indian Health Service), or per capita payments) that tribe members get only if they continue to live on or near the tribe's reservation.

But still, do you stand by your assertion that "you’re condemning the kids born in these places to quasi third world conditions"? Because being able to just move whenever you want to the US legally without even a requirement to inform any authority of the move doesn't strike me as "third world conditions", the essence of which IMHO is the difficulty of becoming a lawful resident of a more competently-run jurisdiction.