Comparatively we can meet people who lived in failed hippy communes, but the successful ones aren't likely to interact with you.
They didn't fall apart, exactly. They're still living as Amish and they're moving to be closer to their families:
> “We wanted there to be an Amish community here, but seems like everybody Amish is more from Ohio or Pennsylvania, where there are more trees,” Rudy Borntreger, the community’s bishop, or elder, explained. “I think it's so open, nobody wants to join us. Now more people decided to move back to Iowa and Minnesota, so kind of for unity's sake.”
Is a temporary commune even a failure? Is a long lived one necessarily a success?
Are there 50 year old hippie communes we haven't heard of?
Yes https://en.wikipedia.org/wiki/The_Farm_(Tennessee)
There are probably others too.
And then of course, the kibbutzim in Israel, though almost all of them have radically transformed themselves since they were founded.