You are living in the past. There is nothing, nor has been for generations forcing anyone to stay on reserve. One thing I can tell you: give me the amount of unaccountable money it takes to sustain someone living hundreds or thousands of kms away from the bulk of the population and transportation links, and I would not be a success, I would be nothing but a welfare case - just like any other ward of the state or any government employee or institution. Business in general and entrepreneurs in particular simply don't work that way.
Since you raise the point though, let me share some experiences.
About 40 years ago I was enroute from my home in the Thompson to Winnipeg. When I landed for fuel in Norway House, the power was off so I couldn't get gas. While waiting, the Manitoba Hydro guys had chartered the Aztek based there to go to another community that also had no power. I was asked to ride right seat, so climbed aboard for the trip. On the way the Hydro guys told me the story: they pay a staff of people to monitor the diesel genset that powers that community but none of those paid to do so ever bother to actually do ANYTHING such as read the fuel or oil levels or top them off. They just radio out to tell Hydro when the power goes out. When we landed I was told to stay and guard the airplane - otherwise the avgas would be drained from every tank before we got back, and it would not be safe for me to be there, as they only needed the Hydro guys to get power on, not me for any reason.
Almost 20 years ago we (JV) built a portable (skid) sub station and supplied a power transformer for one of the Ontario reserves North of Red Lake (up in Treaty 5 country). The purpose was to tap into the nearby transmission lines so this community and two nearby could have much cheaper and more reliable line power instead of off grid diesel gensets. When we arrived with the transformer, it had to be placed off reserve. When I asked why I was told that if it was on one reserve, they would turn the power off to the next one down the line when tribal disputes or just a lost hockey game could get them wound up. We placed, assembled, filled and tested the transformer and left it until the substation skid was delivered. For nearly a year we did not get paid for the sub. When we investigated, the excuse was that the power was not coming down the line. When we investigated further, we found that the transformer and substation had been vandalized to the point where they were both beyond salvageable. Five hours up an ice road, do you think "whitey" drove up there to do that? Yeah, he drove up there and spent millions to give the aboriginal reserve grid power, but the respect shown for that effort was to dodge paying the bill....all the while you can believe the Chief and Council were quite contentedly driving around their shiny new Cadillac (actually Expeditions then), living in their free home, and taking air taxi out to collect their per diems for endless meetings about nothing. Almost two decades later, that reserve still is not on the grid.
Welcome to one small slice of reality.