Thinking about Armageddon 2419 A.D. (Nowlan's 1928 novel that introduced the world to the character later known as Buck Rogers) while listening to the audiobook of the first novel in The Expanse series, I think it would be cool to run a rpg campaign in a sort of updated version of Nowlan's world. Of course, TSR helpfully already updated that world in Buck Rogers XXVc in the late 80s, so that's a resource, but I think I would tweak things in a slightly different direction.
The basic idea is the same, though. Civilization on Earth is pushed to the brink in the 22nd century by climate change and the political and social upheaval that follows it. Eventually war breaks up, and the Western world essentially collapses.
While all this was going down Silicon Valley and other wealthy futurist types had been developing their exit strategy by pushing space colonization through private companies to orbit, the Moon, Mars, and Venus. The forward-thinking government of China gets in on these efforts, and eventually a hybrid, corporate culture emerges on Mars.
So we fast forward a bit to a time where Mars has colonies established in Earth-Luna Lagrange points and is the colonial power seeking to rebuild (and exploit) the backward Earth. Martian colonial types and the Earthers that get with the program live in arcologies (like the Plexmalls of American Flagg!), but outside of those it's all warlords, mutants, and dangerous left-over bio- and cyber-weaponry from any number of wars.
There are also rebels out there. Earthers, sure, but also bioroid and cyber beings trying to escape exploitation by the rapacious Corporation of Mars. The Earth independence forces have secret bases in orbit and if not friends, at least allies on other worlds who would like to check Martian power--through proxies, naturally.
Anyway, beyond the influences mentioned about, others might be film/tv like Andor and Rogue One, Blakes 7, The Creator, Elysium, and games like Transhuman Space and Jovian Chronicles.