Commodity wealth is about supply and demand. If you could really bring back that much mass to Earth you'd drive the value way down. I don't see where debts matter as you wind up with robotic labor that can do 80% of our jobs. We really do have plenty of resources here on Earth and limit surface area. The BULK of the planet is huge compared to just the bit of habital land we live on, not just the surface is huge compared to the land, but the 3 dimensional volume of the planet is filled with PROBABLY anything we need for hundreds of years.

The premise to space mining is that you constantly overcome gravity and vast distances that all cost energy instead of drilling. I don't see many scenarios where space mining is more efficient than the nearly unlimited bulk of the planet.

Sooo occasionally you might pinpoint a high value asteroid and go get it, but a lot of just trash so the logistics here are not the easiest and if you have robots building robots than the cost of commodities has gone down on Earth so much that there isn't demand for space mining.

For space mining to make sense you need the commidity to really be in that much demand that you don't just mine it from Earth and with robotic automation and recyling and limited surface area/peak popultion around 10 billion I don't see it being practical.

Robotic mining means commodities are all worth less because demand is met more easily with more efficient automated processes. The same pattern will happen in all industries.

Money and value are still ONLY about demand, the easiest way to meet demand is all you really need or want to do usually. Space mining is too complex compared to demand, imo. Kind of like nuclear power probably can't beat solar, the simplest thing that gets the job done wins.