In my opinion people really should have jobs. Our ancestors didn't sit around all day. They had "jobs" like hunting and gathering. Jobs and careers give people structure and meaning to their lives; a kid being a trucker is probably better for his mental health than having no job and just being a UBI recipient.
Why does the thing from which we derive meaning have to be a job? Why can't UBI recipients create art, have hobbies, meaningfully interact with their community during their day? Our ancestors didn't sit around - they did all those things, too, and those things also gave them structure and meaning.
I think hobbies are distinctly different from careers. I suck at golf. If I had UBI I might golf all day. I’d still suck. I think you need something that fits your skills that makes you feel like you’re contributing