If everyone consumed like an American we’d need something like 4x Earths. There are not enough resources on this planet unless westerners start scaling back their consumption and members of developing societies scale their ambitions down to match the new, lower consumption models of the West.
Then making that consumption sustainable and reducing waste would be a far better investment than pipe dreams of asteroid mining.
Keep in mind scarcity of resources is not the only issue. If everyone on Earth really ever started consuming as much as Americans then it doesn't matter if there's enough surplus material in space, the ecosystem on Earth would be dead anyway and we'd have much bigger issues.
There's enough resources (especially since they don't just disappear and can be recovered by recycling), afaik, except for food - that's what we're consuming too fast to replenish.
