Colonizing the Moon makes absolutely no sense and it's fascinating to watch otherwise rational people with decent science educations contort themselves into believing otherwise just for the sci-fi trope of living on the Moon.
Maybe in 50 years the Moon can be colonized by machines, but for humans if they really want to experiment with self sufficiency, they can try building Biosphere 3 in the Sahara and see if they can survive for a few weeks without constant support from the outside.
A fully isolated colony anywhere isn't going to happen in our lifetimes. This would be true even if there were another Earth. It would require multiple revolutions in compact software-defined manufacturing and a rethink of supply chains around that core.
McMurdo on the Moon is entirely possible and I think there's a good chance we'll see it. This would get us started trying to live elsewhere and we'd start learning how to deal with the challenges. We'd also find out about the challenges we don't know.
Back in 1999 I worked on a (unfunded) pre-proposal to NASA on "OSCOMAK" (Open Source Community on Manufacturing Knowledge) but, it did not go very far.
https://www.kurtz-fernhout.com/oscomak/
"The project's ultimate long-term goal will be to generate a repository of knowledge that will support the design and creation of space settlements. Three forces -- individual creativity, social collaboration, and technological tools -- will join to create a synergistic effort stronger than any of these forces could produce alone. We hope to use the internet to produce an effect somewhat like that described in "The Skills of Xanadu" by Theodore Sturgeon (available in his book The Golden Helix). We will develop software tools to enable the creation of this knowledge repository: to collect, organize, and present information in a way that encourages collaboration and provides immediate benefit. Manufacturing "recipes" will form the core elements of the repository. We will also seed the repository, interact with participants, and oversee the evolution of the repository. You can read a paper we presented on this project in the Proceedings of the Thirteenth SSI/Princeton Conference on Space Manufacturing May 7-9, 2001, which we have made available on the web..."
See also my comment here: https://news.ycombinator.com/item?id=15736225 "... So where is a key area of research that should be a priority among NASA and Billionaires, but is not heavily pursued? The issue is what to do in space once you have gotten there. Because if there is a reason to be in space, then people and collectives will work to get there. And the reality is, that right now, if we could get there, there is nothing to do there short of look around and come back. And if that were the case, Space would not deserve much more investment than say tourism to Mt. Everest. The reality is that we don't know how to support human life in space -- in large part because we have only spent a pittance on thinking about that issue systematically compared to the issues of CATS and Planetary Exploration. Frankly, while we support human life on earth, we have very little meta-knowledge formally about how to do even that. And, most of figuring out how to support human life in space at a nuts and bolts level requires non-sexy activities like sitting around and staring out the window, talking, sending emails, building databases, building software tools, building some small physical prototypes on tabletops and outdoors, and just plain thinking (the hard stuff). This is all the preparation needed for the spiritual voyage into the (physical) heavens. Biosphere II was an excellent start in some ways, although the science mission was a bit dodgy at first and it seems Columbia (the recipient) seems about to abandon that effort for cost reasons --- and in any case, Biosphere II focuses on the wrong question -- we know biospheres can work and replicate (although scale is an issue) -- what we don't know is how to replicate the mechanical infrastructure (e.g. glass pane making machinery) behind them. A lot more money has gone into studying ecosystem food webs than industrial ecologies of pipe webs and assembly line webs (and frankly, a lot of people don't want their "proprietary" manufacturing processes studied or gossiped about by academics.) ..."
Maybe in 50 years the Moon can be colonized by machines, but for humans if they really want to experiment with self sufficiency, they can try building Biosphere 3 in the Sahara and see if they can survive for a few weeks without constant support from the outside.
https://en.wikipedia.org/wiki/Biosphere_2