It's quite a bit more than that. The indigenous relationship to the land and environment is inherent to their identity and culture. It's one of respect and reverence. Capitalist economies around the world have a relationship with the environment predicated entirely on exploitation: exploitation of the land, exploitation of resources, exploitation of people. When they talk about indigenous sovereignty, they're referencing a way of conceptualizing humanity's relationship to the natural environment that is symbiotic, deeply reverent, and intrinsic to our health, well-being, and survival.
That’s a very romantic notion, but total bullshit. Indigenous peoples exploit resources here as much as anyone else when they have the means to do so.