I would argue the real question is sustainability. The universe is finite.

Right, the concern is not unfounded, but maybe a bit counterproductive without context. There are many resources we already exploit very inefficiently, and the sustainability of those is a real worry, but the general carrying capacity of Earth and the solar system is really really vastly huge, we just do very dumb things to ourselves economically speaking. (This is of course the coordination problem, and it's hard, as human behavior is what it is.)

Last I heard it was expanding -- and the expansion was accelerating.

When we looked at the most empty spot we could find with the best camera ever built, we saw more universe than we could even have imagined.

Earth, ok, that's somewhat finite. Yet we're literally barely scratching its surface.