The real problem with UBI is the people who need help the most are least able to help themselves. I have friends who are mentally unable to advance beyond assistant usher at the movie theater (the head usher is some 16 year old kid who started two weeks ago). I have a friend who is convinced the CIA had the doctors put a bug in their knee while doing surgery.
These are the people that need the most help, and UBI won't help them. Both will fall for scams, and otherwise not provide for their basic needs if just given money.
UBI can help the disabled who are mentally competent. There are many things that I do daily that required working eyes/ears/limbs. Some of them society can make "reasonable accommodation" for, but some of them are not possible given that disability.
UBI can also help those who had "bad luck". Though here we quickly get into people that it is hard to be sympathetic towards. I know of a lot of people that are poor because they continually waste their money on drugs (legal and otherwise - not medically required), gambling, trinkets... They may never be rich, but a different spending habit could change their life. (You will note here that I'm injecting my own value judgement on their lifestyle)