The thing about companies mining in space is actually interesting. As of right now, a lot of our technologies are held back based on not having enough access to rare-earth metals such as gold, lithium, platinum, etc. Perhaps this is even a part of the reason Elon Musk became a part of SpaceX, knowing Tesla's electric cars were going to need a lot of lithium for their batteries; so much so that they're building a gigafactory to double the global output of lithium batteries in the next 2 years, and even build further factories elsewhere based on demand.

I haven't done the math, but I think, if with our current output of lithium batteries we're already becoming aware of our limit in lithium reserves, a yearly doubling, tripling, etc. the yearly output will make it as apparent, if not more so than our current oil crisis. And it's not as if we'll go back to oil, or stop using rare-earth metals. We'll need to venture into the void of space collecting them from wherever we can, and bringing them back to our home (wherever that may be at the time).

This however invokes a further question in me. If we were to be forced to evacuate the earth and live somewhere else, would we still continue with earth-based industry? By that time space travel will presumably be a better-known science and possibly be able to be set up and performed by robots, and robotic engineering will be advanced enough that things like assembly lines will be able to run autonomously with minimal human interaction. I think it would be interesting to find out if the human government would decide to further destroy earth as a lost cause and to avoid damaging other planets needlessly, or if we'd decide to spread it through the solar system to do minimal impact everywhere. Perhaps even have industrial sectors based in moon and planet-like satellites that can be landed on and maintained manually, but wouldn't require things such as cooling, and would maintain the beauty of all the planets.