Obviously people will need to be working still, a time when all work is done for us is long way off. Besides, there were studies made on this and most people would still work in some capacity (not all, obviously) - but with you getting money to cover your needs you could quit thenjob you just have for the money and do something you enjoy. Or keep the job you do just for money if lots of money is important to you - but you would be free to take sabatical if you’d start burning out without fear - because you would still have the UBI even if you spent all your money and didn’t save any.
Especially now with raise of AI this is something that will be needed sooner rather than later - question is when, not if. And another question is how will humanity fuck it up - because that’s what wedo best and the theory behind it sounds too good to be true.