Or if we have the power to terraform Mars, and not just be stuck in a space colony out there, but be able to explore the planet freely, why not just terraform E

Or if we have the power to terraform Mars, and not just be stuck in a space colony out there, but be able to explore the planet freely, why not just terraform Earth back to Earth [1]? [1] https://www.youtube.com/watch?v=7XdkKMhAdnA&t=458s https://www.youtube.com/watch?v=7XdkKMhAdnA&t=458s (Neil deGrasse Tyson)