Do you believe we have landers on Mars?
Of course—if you read the links you would know exactly what the issue is—human landings on the Moon (and of course the same issues for Mars).
The experts there argue that the only way to do this is to have robots build underground bases and infrastructure so that humans can function there.
In addition the landing craft (with human occupants) will require shielding with nanotechnology. Likewise the space suits will require nanotechnology as well.
Here is an article about what NASA is dealing with today just on the spacesuit issue:
https://qz.com/2046840/a-1-billion-space-suit-is-holding-up-nasas-2024-moon-landing/