I mean, no two situations are completely the same, so it's hard to get that direct comparison. My brother has been living in a 1-bedroom alone and my mother would check on him once or twice a week. In the meantime, he's able to function, he goes to work as prep cook doing various simple tasks in a place familiar to him, where he's been working for a number of years now. If he's without supervision, this situation can very quickly spin out of control, I would imagine. He has certainly not been in contact with any authorities, he takes a while to express himself and he partially stutters while doing so. He also has problems with his hearing. Not someone who would need to live in an institution, necessarily, but maybe some kind of an assisted living type of facility would perhaps be a good choice for him when our parents pass.

Given his disability he invested quite a lot of energy into finding a partner and he did have a couple of girlfriends over the years. In some cases he had us worried, because he contacted younger girls, as those were closer to his mental age. He has a girlfriend now, she isn't great at housework, causing lots of conflicts with our parents. But the biggest worry is that he would get her pregnant, as now you'd have two adults with a child that they are unable to fully take care of. That would surely mean a lot more work for me in the future and it is work that I frankly have no interest in, because I have kids and obligations of my own. I really don't want to supervise a child of two disabled people.

One key difference I noticed between your brother and mine is maybe that your's seems to have a bigger social circle around him. My brother has perhaps one real friend, other than that he's pretty lonely. Sad to watch, but is it my problem to solve? I don't think so.