Mainly, the downside is dealing with the 'bux cunts. They always get harsher when times are bad.
Even if one is put on the shelf and not on appointments anymore, one still has to pass assessments where they are desperate to force one off the shelf, and off the 'bux altogether. On top of that, they've started to review my claim every fucking year, which takes weeks for no reason, and forces me to show up at the office with my fucking ID, because I've always been too poorfag to own a passport, that I would never use for travel anyway.
For these and many other reasons, I wish we all had a truly no-strings UBI in the West. It would give my temporary peace some permanence, at last.