Landing on Mars is the artifact of all of the innovation required to get to Mars. We benefit from the innovations, not the landing per se.
Memory foam, smart phone cameras, tech miniaturization in general, GPS, baby formula, cordless tools... just a tiny sliver of things we use daily that are directly attributable to the pursuit of space travel.
It is far from useless
I fully support humans landing on Mars and large budgets but I don't think anything gets exaggerated in these discussions quite like the commercial technology ROI of space programs.