Best case scenario, it'll turn out like space travel: something that we "did already" but that wasn't nearly as interesting as all those wild-eyed dreamers hoped.

I don't see that happening in this context, though; with space travel, we "cheated" our way to a spectacular short-term goal by using politically motivated blank checks while ignoring longer-term economics. Competing venture capitalists are less likely to ignore long-term economics, and any "cheating" is likely to mean shortcuts with regards to safety, not sustainability.