May not be a bad thing if the number of jobs had reduced a lot due to Ai/robotics.
One of the benefits proposed of UBI is that it supports a return to a time when it was far more within reach of people to have more time and less money stress.
Its very simple in theory, very difficult in practice.
You then get into the realms of things like jury service. IMO you should maybe be able to accept UBI or some alternate scheme, (alternate is very much like now, but with a wealth tax)
If you accept UBI then you have to give up, say 30 days a year which you may be called up to to provide for jury service, environmental activities (eg say cleaning rivers up) that sort of thing.
Its really quite radical but if we are going to see say 40% less employment required then somehow ensuring that everyone survives, whilst still providing "enough carrot" for those jobs that need to be done, and not making it too attractive to do nothing at all is a hell of a balancing act to perform.