Well in my opinion, space would be the the most logical next step for us to explore and harness (especially when we look at the density of elements we can find in some asteroids or what could be found on planets in other systems) but like many said before it would just make some private companies richer.
Like the person before said, there is also the problem of pollution (we already having issues with pollution on our only planet so I don’t even want to think what could possibly be done if we had another planet just for harvesting ressources).
“Conquering” space is at the moment a great idea and people dream about it, I’ll be honest if I had the opportunity to be among the pioneers to start a colony on Mars ( which is the most likely scenario in the future, at first), I would go even if there is no guarantee of coming back. But the remains fiction for now, with the exception of asteroids mining I don’t think we can properly settle other planets while we are still struggling on our home one (with all the wars etc).
And of course there’s the technological limitations, nuclear fission is good but I don’t think we could venture in space without a new source of energy. And we would also need alloys, a steady source of food for the duration of the travels because cryogenic sleep or FTL travels aren’t gonna be a thing before a lot of time if even possible.
TL;DR: Space exploration is humanity’s logical next step, but it risks worsening inequality and pollution. While colonizing other planets is a great idea, it’s still far beyond our current technological and societal capabilities. For now, asteroid mining seems more realistic than true interplanetary settlement but we gotta do it well for the benefit of humanity and not just some corporations.