settlement on Mars/Moon is a multi-disciplinary act! figuring out efficient and safe geothermal or nuclear or whatever technology to improve Earth's life, definitely translates to future settlements... so why not do it here? it isn't about eradicating suffering, as it's part of the existence (probably) but it's about providing a decent life for everyone
(I assume, but have no hard numbers, that it's also cheaper to send hydroponic systems to Mars than to ship food regularly: conditional on that, also to ship an autonomous food factory).
Going to Mars long term also requires the shipping cost to space is reduced so much that the cost to LEO is competitive with current airline rates, so when I say "drop an autonomous pod anywhere" I really do mean anywhere — Sudan, Malawi, Nepal, Everest, Antarctica, are all much easier than Olympus Mons.
Perhaps it’s pessimistic, but I have little faith that even a single country will eradicate suffering within its own borders, let alone all countries coming together to cooperate and eliminate it globally. If we wait until all earthly problems are solved before going into space, we’ll simply never go to space. At some point something will happen that will stop launches entirely, we’ll lose our institutional knowledge of rocketry and spaceflight, and putting things in orbit (let alone people on the moon) will become an impossibility again.