I think we should fix Earth AND a portion should move to Mars. We should also create tech that allows inter planatery travel at a viable timeframe because the people in mars will get homesick eventually. Then we will have two planets and a model for how to create living environments in more. Then we can expand and become a multi planetary species. But Earth is our home and origin we should never just abandon it fully
Just a guy who doesn't want to be bored. Also