The idea is to give people enough of a safety net that they don't starve to death. But really, it's kinda crap to live in a shared apartment with a bunch of broke college students, living off giant bags of potatoes. Most of us have done that, and now that we can afford not to, we don't.

I'm sure there will be plenty of people with low enough ambition that they'll just stay there, subsisting. But I don't doubt they'd be doing that in their mom's basement without basic income, so I imagine that society will survive just fine.