The problem is that Serious Space Enterprise is very costly, ongoing, relative to the actual return on the operation. Not the invention of the tech to get you

The problem is that Serious Space Enterprise is very costly, ongoing, relative to the actual return on the operation. Not the invention of the tech to get you there. We've probably made most of what we'll get. In the sense of, "If there were a gold brick on Mars, would it make sense from the cost of the energy required to move the brick from Mars to some orbit and down to the surface of the Earth, versus the comparative energy required to go out, dig for, and refine the same quantity of the gold from the place we're just standing on right now?" manner, to be more specific. Once you start thinking in that fashion, you can start asking yourself, "Exactly what object or material do I want to bring back from Mars, and could I do it more cheaply in, say, Minnesota?" Like in the way that once lab-made diamonds which are identical to mined diamonds and become cheaper, the mining is going to slow down unless the process is encumbered by tariffs, regulation, artificial constraints to preserve a business are imposed.