A UBI experiment will probably need 50 years or more to determine what the long term consequences will be.
https://scholars.org/brief/what-happens-poor-families-when-t...
I'd call it a success if about half the adults end up working and the other half stay at home, just like people used to do 100 years ago... except this time, both men and women should be free to choose which side they want to be on.
while this may be true, I think it's somewhat of a false dichotomy. If we get to the point where UBI is implemented, I don't think the only two choices will be 'continue working or mope around'.
There are hundreds of thousands of ways to create value in society, and they don't have to be tied to the notion of working in exchange for money for survival.
I think the fear is that a small portion of society will be doing all the work to support the 'lazy ones'. It's understandable, but I think it is entirely possible to avoid that situation. Of course, it would require a fundamental shift in our worldly view (i.e. from individual success to shared success), but those discussions are hard and usually get shut down as 'commie crap'.