(I just read "A City On Mars" by the Weinersmiths, which concludes life in space will be pretty awful at least at first and will endanger earth, so why do we want to do this again?)
It has been widely noted that we got to the moon very quickly, then apparently did nothing but bureaucratic bumbling for fifty years.
Perhaps a better way to look at it is what we CAN do, rather than what we DO do. In 1969 we COULD get to the moon, and we proved it by actually doing it, but it was extremely expensive and essentially a camping trip. Ever since then we still could, but there wasn't any motive to do such a camping trip.
Recently SpaceX has been developing rockets that can make such camping trips much more affordable. Computing advances make some of this stuff much easier than it used to be.
But can we now do anything more than a camping trip? Absolutely not.
Would cheap spaceflight advance these? Maybe by giving a compelling use case, yes. But not by providing opportunity to test them. Closed terrariums capable of supporting mammals? Easily testable on earth, we just haven't. Robotic mining and manufacturing? Ditto, but that one seems to be making progress. Space solar cells? The best article I found said ship up the ingredients then 3d print it there. We're still firmly in the zone of camping trips.
The only bit of space that is hard to test on earth is the longterm effects of no gravity. We've already confirmed they're not good, but only rotating space stations can make that one go away. Food and manufacturing are much easier to debug on earth and the moon.
Antarctica has been experimenting with growing enough food to feed people. Mostly salad. They haven't scaled up enough so far to be anywhere near self sufficient, but they do seem to be making some progress. I didn't see any references to them recycling poop rather than using flown-in fertilizers.
What's the smallest closed terrarium possible for supporting a human being? Each human currently needs at least half an acre of productive farm for food, usually much more. But food production is improving. Oxygen is already produced chemically rather than by plants for ISS and submarines. If you could chemically produce food, it could really be quite small, then comfortable elbow room becomes the limiting factor rather than food production. Energy requirements could also be scaled down ... the human metabolism is about 80 watts, so that's the theoretical minimum. We are far far far from the limits. Space colonies don't require reaching the limits, but they do require getting closer than we are now.
If we had space colonies, the colonies will eventually decide to drop rocks on earth. So there's a downside to doing it. But I don't see any downside to being able to do it. We should learn to be able to. And most of the learning to be done can be done on earth. A lot of that is learning efficient usage and recycling and food production, which are useful here on earth too.
From this perspective, what is done is not as important as what is learned, and what is learned only matters if it gets indexed and remembered, even if other options immediately seem better. This takes a dim view of companies building propietery solutions, especially when the company decides to discard projects and go a different direction. It likes open source software. It's a very familiar world view: it's the same one where you want to attach your name to theorems or patents or music or books or research papers so you have contributed to mankind's ongoing culture after you're gone.