I love the idea of it, a friend tried to do it 30 years ago but it was hard to find anywhere suitable. The only thing, if you buy into it, is that it may be harder to sell for you if you change your mind, or for your inheritors if you pass away there.
Or I would happily go into a sheltered housing apartment if I could have a bit of garden, and as long as the walls were not so thin that you could hear other people's conversations and three tv's going all day (which is the case with someone I know), and as long as the service charge was affordable. I do worry that I will have a stroke or heart attack and be found dead only when the smell alerts a passer by!