How do we profit off of this? Manufacturing?
I understand why you would want to build a widget factory in China, but what possible goods could we produce on Mars, that wouldn't be easier to produce on Earth?
I understand the situation of rare-metal shortage, but many of them are rare because extracting them requires uneconomical amounts of energy. Mining them from space (And good luck finding an asteroid with more then traces of Gallium) would still require uneconomical amounts of energy.
On Mars? Probably none. In LEO? That might be a different topic. In general, you don't want to move up the gravity well if you can avoid it.
A naive person in me hopes that as space manufacturing becomes an option, the terrestrial manufacturing costs will rise significantly as people will no longer be willing to tolerate the abuse of humans and ecosystem alike that today's manufacturing is.
Innovation is not just about making completely new things possible, it's also about improving the things you can do, making them cheaper: Making it so that you can do them in a way that does make economic sense.
This is just the first step of several. The first step is worth doing, even if you won't cross the finish line while doing it.