Effortless oxygen, effortless radiation protection, effortless temp. range.
I believe we tend to forget exactly how much Mother Earth provides us. And how fragile we are. Water, food, all the basics. For a small population, without any effort. Look at the Masai in Tanzania and Kenya up to about 100 years ago. Absolutely no need to work.
Replacing just that stuff would be difficult.
A "colony" might last a little while, but not long.
