It’s important to remember that most movements and experiments fail, same reason countries and companies also fail. A lot of them failed due to mismanagement, idealogical disputes, children not sticking around (ie no new members) etc. building sustainable communities is hard and not a unique problem for communes.
btw these are all the same reasons open source projects fail yet we wouldn’t call open source a failure despite it having all the same problems and looking more like communism than capitalism.
Also you’re overstating the failure rate. Amana Society, Inc is a cooperative structure that evolved from a commune. REI is also a cooperative corporate structure although not quite like a commune. So clearly there’s a path to evolve to that’s sustainable and does work and looks quite a bit different from capitalism. And there’s a difference between communal living and cooperative commercial entity which is good to separate.