You'd force them to lease it to the colonists? What if they don't want to lease it, what if they just want to keep it for themselves cause it's theirs?
If we acknowledge it’s their land, it’s their land and they can do what they want with it. So let’s just issue superficial statements to look like we care and do what we want with stolen land instead.
From traditional indigenous viewpoints, it is inherently problematic for anyone to "own" land, indigenous or not. From their original perspective, nature cannot be owned by anyone, as it does not belong to anyone. Humans are simply a part of nature and have a responsibility to act as stewards to protect it. It was the act of colonization, along with the forced exchange of rights, that parcels of nature became a thing to be owned at all. Indigenous people started to fight to "own" land in order to protect it, and thus came the idea that it was stolen at all.
It's not to say that we aren't on stolen land, we are. But even
if we were to give all the land back to the indigenous people, it wouldn't fix the massive gap in understanding that exists. But none of this fits within our current understandings of Eurocentric governance, legality, ownership, resource extraction, and social structures.
If we
really respected indigenous people, we wouldn't simply give their land back, we'd structure our governance ideals around respecting nature and our place within it. We'd fight to dramatically expand the amount and size of protected parks, limit our dependence on unsustainable resources, and act to fix the generational oppression of indigenous people the government has created (i.e. education, housing, and clean water).