Yes, there are many potential benefits to having a Basic Income system. However, much as you might dislike the idea of some people living in a van and not having a job, I think it would require draconian measures to prevent it ever happening at all. But what Basic Income can do is give people an improved incentive to find work, because finding work won’t cause them to lose any of their Basic Income. It’s a carrot approach, rather than a stick approach — which is probably much better, if we want to maintain a free society.
And remember that just because a ‘hippy’ living in a van doesn’t have an official job, this doesn’t necessarily mean they aren’t making an important contribution to society — or that they won’t make an important contribution in the future. I wonder how many great contributors (musicians and writers, for example) spent time living in a van (or equivalent) at some point in their lives.