A manned mission to Mars isn't even on the table yet (sorry, Elon) until we solve several huge problems, including cosmic radiation, landing heavy payloads, and a feasible alternative to chemical propulsion (most likely nuclear, but untested).

Add to the list that martian dust contains a massive amount of carcinogens meaning any air/dust lock has to be an ISO-6 clean room.

Sure it is a "solved" problem but all the solutions are very heavy.

Manned mission to Mars is a fad.

But it is important fad just like space mining.

We as humanity have to believe we are not in zero sum game to stay decent…

Unfortunately last years are showing us how ugly it is with rare earth elements, energy etc. It is also showing what you wrote is true. No one really believes that we can affordably space mine for rare earth and no one believes in Martian colonization that would bring tangible benefits.

Not to mention supplying astronauts with food and managing their waste for 6+ months.