There are several points of UBI according to me: 1) It simplifies the social support system and makes it more market oriented. Maybe it doesn't eliminate needs-based support totally, but that's a good goal. Need-based support creates bad incentives because it encourages people to be needy. 2) It gives people freedom to take risks and pursue what they find important. Right now many people do pointless work; sometimes…
This needs some unpacking, I think.
Though there is a way in which this is true, it's not the way that most right-wing pundits would have us all believe. The commonly-sold myth of welfare is that there are people for whom welfare (or whatever other "needs-based support") is something they desire, so they kick back and don't try to improve themselves, so that they stay needy—essentially, they deliberately become moochers leeching off the system.
The research I've seen indicates that if people like that exist, they are a rounding error on the books.
What's much, much more common is people who desperately need their support being forced to avoid bettering themselves, lest they fall into the hole between "the government admits that you need this" and "you can actually provide for yourself." (One particular example I've heard of is a disability system where owning more than $2000 in assets of any kind results in you getting kicked out of the system permanently.)
Now, what's also much more common is people who genuinely need the support being unable to get together the wherewithal to prove that they do need it. (For instance, a form must be submitted in person, or an in-person interview is required, but the person doesn't own a car, or the disability they're trying to prove made them unable to drive, or the office that they have to get to is only open during the hours they work and missing a shift will get them fired...)
Needs-based support is bad, and we need to move away from it as much as possible to universal support, but it's not really because of malicious people preying on the system.