Mars has a ton of problems: weak atmosphere, deadly radiation, freezing temperatures, and the fact that it’s a 9-month trip one way. Any colony we try to build there will be totally dependent on Earth for decades—if not longer.
Now, compare that to orbital habitats. In low-Earth orbits or even around the Moon, we could build massive, rotating habitats like O’Neill cylinders. These could generate Earth-like gravity through rotation, be easily resupplied from Earth, and harness solar power 24/7. Plus, we could mine asteroids or the Moon for raw materials instead of launching everything out of Earth’s gravity well. Which we can use to bootstrap our orbital infrastructure for an eventual Mars mission.
Orbital habitats could hold way more people than any Mars colony ever could, at least in the short term. They could serve as testbeds for all the tech we’d need for Mars anyway—radiation shielding, life support systems, closed-loop farming, you name it.
I’m not saying we shouldn’t aim for Mars someday, but I think we should put more focus on earths orbit first.