Mars really just ends up being a science prestige project for the country or company funding its missions. I suspect most country based missions would follow the Antarctica model where dual use capabilities are built out “for science” and space infrastructure gets built including an Aldrin Cycle ships.

I suspect someone like Musk or a reasonably powerful organization is going to do back of the napkin math and figures out terra forming goes from sci-fi fantasy to feasible. This will likely come around as asteroid miners can get to the Oort Cloud and get access to large amounts of frozen water, methane, and carbon dioxide. As Mars is terra formed, the planet gains value and interest from countries and organizations to create their own colony on the planet.