«The problem it doesn't solve is what people will do with their time.»

What would you do with your time if you weren't required to work for your living? I'd spend more time writing fiction and videogames, personally. Others want to act, write poetry, create art, perform music, romance, raise kids, the list extends out to so many extremes of human expression and desire.

I'd probably read more books and play more videogames and attend more concerts, too. There would certainly be a lot more Netflix binging, in general. But the problem here is that people see such culture (leisure) as sinful/wasteful, rather than a goal, a possibly better human existence. If more people have leisure time, so what?

At some point we have to admit to ourselves (as this is deep in the American DNA at this point) that the Puritans were wrong and backbreaking labor is not the end all/be all of human experience. It's not a more "pure" life to work ourselves to death and it's not "guilty" or "irrational" or "wasteful" to balance some pleasure and leisure into one's life. People should not have to "earn" a right to the bottom rungs of Maslow's Hierarchy: they should have food, shelter, safety, health. Why should "work" be an entry bar to claiming one's basic rights as a human being in a caring society?

The concept of "basic income" is that everyone gets it, regardless of qualification. If people want to earn income over and above that, they are welcome to: there will still be startups and companies and projects that will (need to) pay for labor. If people want to live on the bare minimum that "basic income" provides for them and spend the rest of their life in relative leisure, then let them. What harm does that do to society? If companies have such a great need for that extra labor they would be missing they can pay the value that that loss of leisure is actually worth and lure the "lazy" out of leisure through enough incentive.

If someone tries to leave beyond their means and uses "basic income" as a crutch they'll quickly find themselves dealing with the same disincentives that poor people already face: bad credit, collections agency, the prison-industrial complex.

Already productivity statistics are telling us that there are fewer jobs needed than people that exist in this country, and with increasing automation this trend will only get worse. We can't enforce 100% employment, and why should we? Instead, we need a solution for a (much) less than 100% employment world and punishing people with crippling poverty and debt seems like a far less useful solution than whining that maybe some people might find a way to take their basic income, find some shelter and a lifestyle that is sustainable under it, and binge watch Netflix for the rest of their lives without ever "working a job".

What you perceive as a problem here is a failed assumption: the Puritan belief that people only live meaningful (sinless) lives if they devote themselves to some hateful job and work to earn their way to a better life (heaven for the Puritans; a leisure-full retirement if they are lucky after putting their nose to the grindstone, in the case of the classic American middle class propaganda).

Sorry for the long rant here, but it's just something that I think we have a hard time talking about in America precisely because we've got a bundle of culturally foundational DNA that makes it tough to talk about without first attacking those foundational assumptions. Hopefully, maybe this helps explain what you are missing in the concept?