space is infinite, and as such, infinite growth is possible

• A finite portion of the universe is within our cosmological horizon. The universe is in fact not infinite.

• The speed of light (the speed of causality) places hard limits on over what distances economies can operate on an interstellar scale.

• Interstellar travel is not a solution to population growth and resource depletion, as it costs orders of magnitude more energy to ship someone across interstellar distances than to keep them alive for millennia at absurd comfort levels.

• You can keep your economy localized and instead go out and grab resources from distant Suns, but that has real diminishing returns. And if you cram too much matter in too small a volume of space, you cook your civilization in its own waste heat or collapse it into a black hole.

Space travel, especially interstellar space travel, is not a cheat code to infinite resources. Colonizing distant stars is more like throwing seeds into the wind than it is extending your own civilization by settling the next valley over. When you start an interstellar colony, you're founding a new civilization, and ultimately a new species, not building an extension to your own. The speed of causality demands this.

Sure, you can hand waive these concerns away by speculating about faster than light travel. But at that point, you might as well be arguing that we'll solve all our resource problems by building a perpetual motion machine. If you can build one, you can build the other.

WoodScientist already hit a bunch of relevant points, to which I'll add:

Spaceflight requires immense amounts of money and capital.

So... it'll only ever be meaningfully done by either nationstates or megacorps, likely both in collab, and likely necessarily is part of the MIC in a very major way.

That means that without massive societal/political/governance reform... you end up with Weyland-Yutani, but with the quality control of Boeing and SpaceX.

Not ideal, arguably guaranteed to be so massively long run inefficient, and dependant on an extreme wealth imbalanced underlying economy/society... that it ends up functionally destroying Earth via climate change / nuclear apocalypse, and if any spaceborne humanity remains... they're the Enclave from Fallout, basically.