> it always leads to more resource use

It does, but this due to the demand created by humans. If you create a technologically advanced civilization, with robots doing a lot of the work, and considering their lack of desire to own things like pretty houses, it could be possible to scale down civilization to a few select millions in such a way that the entire system is then respecting earth's resources.

If you were to ship a big group of people through the galaxy, you'd also have to put some constraints on how many people will be on that ship, yet it will have to function regardless of how little people exist on that ship. The same could be applied to earth.

This would also give animals more room on this planet.