Sure, those people exist, that is fine. Some people do that now and far beyond their 20s: just hitch/bike/van around and do the odd job for a few days and live off that the rest of the time. There are communities where I live who allow anyone to come in and clean and cook together so you can stay and eat for $0. That is without basic income so it will happen with too. Thats a tiny minority. Most will get bored, loney, fed up etc if they even 'dare' to start such a life.