How is Homeworld still not completely depleted?

Starting of, yes I am well aware that Homeworld has severely dwindling resources. However, it doesn't seem to be completely deleted as there still does seem to be Gem production going on.

How is it even still able to? I mean, the planet around the Moon base was already completely depleted, and Homeworld has been mined for much, much longer. Is Homeworld just a uniquely resource-rich planet making it take much longer for it to become depleted?