The capacity to make Mars work, necessarily means we develop the capacity to drop an autonomous pod anywhere (on Earth or Mars) that can make fuel from the air and use local dirt to either fashion a complete shelter or at least place a protective layer over a lightweight one from 50 million miles away.

(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.