If carbon nanotubes become important , we could use the venus CO2 to make carbon nanotubes, space elevators.
The future of space colonizations depends on how much our species is dependent on gravity and how much gravity we need to stay healthy. China sent a woman with the very specific mission of giving birth to a child in space, but we had no news on that anymore. Probably the fetus died , or baby was heavily disabled and they didnt want to show it.
A long term colony would be inviable without childbirth at the place. Even if people dont age anymore, accidents will still happen . If we want to make human species independent from Earth, children have to be born in other places, not only Earth. We have a few options, if children cant be born and raised in very low gravity:
1 rotation space stations : vulnerable to asteroids, comets and debris, resources would still have to come from asteroids , planets and moons.
2 Venus: closer gravity to earth , so its likely the difference in gravity wont affect human body that much. Its thick atmosfere would protect from asteroids , and heat and pressure resistent robots wouldnt have to reach escape velocity to reach cloud cities. They could bring resources from the planets surface.
3 Saturn: yeah the planet itself . Its gravity is close to earth´s gravity.On this forum, they discuss how to colonize saturn : https://forum.kerbal...planets-saturn/
We wont colonize saturn on this century , but it was interesting to read what they wrote on this link