I think that Mars is overrated. It is smaller than Earth, and way more difficult to live there, so we would get like 30% extra space for 1000 times the cost per

I think that Mars is overrated. It is smaller than Earth, and way more difficult to live there, so we would get like 30% extra space for 1000 times the cost per square meter. And then what? We do not have a third planet like that nearby. Mercury and Venus are too hot. Jupiter and Saturn are gas with no solid surface. Uranus and Neptune are ice. The next solar system is way too far. I suspect that if we ever get the ability to travel to the next solar system, it will probably be easier to just stay in space, and only use the planets to mine the resources. Even for that, asteroids may be more convenient. So, from this perspective, Earth is, and will remain, unique.