I would imagine capitalism is on its last legs, as this trajectory is simply unsustainable. Or are we just going to continue down this path until a handful of people like Bezos, Musk, Branson, and Ma own absolutely everything and everyone else is a peasant?

It's not like there's going to be huge free market competition going on when Bezos starts mining asteroids as bit of a high bar to entry on that one. And some of those asteroids have literally quadrillions of dollars worth of materials in them, far more than all the wealth on the earth.