No sarcasm intended here: Is the highest abstracted benefit of Universal basic income (other than the benefit to those that receive the basic income) that you cut out the middle person in social welfare distribution?
There are a lot of labor market benefits as well; one of the big problems with means-tested programs is that they screw up the tax structure at the low end of the income scale. If your options are being jobless receiving welfare or getting a job that forces you out of welfare, there's a large disincentive to seek work. You would be paying an effective tax rate of ~100% by losing that payment.