I think its a great idea.
It would self fund - via tax, mostly on the big corporations whose profits would increase because:
AI costs less.
People choosing to work actively want to work - you don't have to spend money chasing them to work, you don't have to spend money on them going off long term sick through stress.
Fewer but better quality employees who want to work means more WFH, smaller workforce, smaller premises to pay for.
Those who want to work will do a good job, and companies will have to provide good working conditions and attractive benefits. They will make more accessible work places, the work culture will be far healthier, we will see far fewer long term sick stressed people, more people job sharing with a healthy work/life balance.
Those who can't easily work through disability will have enough to live on and are more likely to find part time accessible work that fits their requirements.
Those who can't work at all will be supported.
Those who do not want to work can choose to do that and will be cheaper for the goverment to sustain as trying to force those who do not want to work into jobs is very expensive. Ok they won't have cash for the extras and goodies in life, just a decent basic standard of living... but without the fear of being forced into work they don't like/can't do/don't want, many will end up doing paid work here and there and voluntary work as there is no fear of having their benefits lifeline snatched away.
Theres this fear that everyone would down tools and sit on their arses - but that just isn't the case. Most people want to do something with their day and feel better if they are productive.
Some of the people who are terrified of work, have no skills, poor education, end up on benefits and avoiding work actually expend MORE effort on not working, than they would if they could just work one or two days a week.
Because employers would have to be more flexible and make working more attractive, there would be more opportunities for the 'want to work a little bit' people.
We'd also see more volunteers, which we really need!
However I don't see it happening because:
The power that is in the hands of those who cannot STAND to see someone apparently get something for nothing is huge.
The dramatic change to work culture and employers expected to make working attractive to people who do not HAVE to work, they simply WANT to work... is too much for them to stand.