Exactly this. Someone said further back, there is some middle ground between them leaving home at 18 and never coming back - and staying with mum and dad forever, living off them, and never learning to be an adult. But to be quite honest, if you are an adult who is in your mid to late 30s or older, and you've moved back home more than once and you're still there - living with your parents (because you've not been able to keep your own home, or stay in a relationship, (or job) long term, and you are unable to survive on your own without parental help and money,) then to be quite honest, you are failing in life and you need to sort yourself out.
Like I said, this woman I know: her daughter is in her mid 30s and has left, and come back 3 times. If someone's in their late 20s/even early 30s, and has never left home, and is still living with their parents (because they haven't met anybody yet,) then that's fine. But somebody who keeps getting into different relationships, moving into different houses/flats, and then keeps coming back to their parents again and again, and is still stuck at home at nearly 40 - or older, I just think that's very slightly pathetic to be honest.
My aunt has a friend who she has known for 50 years. She has a son who is in his mid 60s now. He lives with her still - she is 85, and she waits on him hand and foot, and he gives her fuck-all. He does nothing for her, and he hasn't had a job since he was in his mid 40s. (15-ish years.) He didn't leave home for the first time til he was 35, and he left and came back twice between then and his mid 40s.. Only stayed away 6-10 months each time. Had just one relationship (for a year.) That's the longest any woman can stand the lazy fucker..
He has lived off my aunt's friend almost all of his life (his dad died 30 years ago,) and as I said, he has never paid any board money, he never does anything for her, and he is a lazy entitled c*nt who has only worked for about 6 to 7 years out of his 45-ish years of work life. He's a horrible lazy entitled twat, who has been kept by his mum for most of his life... Unsurprisingly in his early 60s, he has been single for about 24-25 years. No woman will ever want him!