The biggest argument for universal income: avoiding economies of dependency for low skilled people.
Would work only if paired with re-skilling, though, because people get depressed if they just do nothing.
Seriously though: UBI would encourage more working without registration. What you can already see with students where their parents pay their education. Often times they just work on the side "illegally". And a whole lot of other issues that come with UBI. Additional government dependency and so on. Advocates for UBI are like advocates for roundabouts really. If properly planned it could be a non consensual help. But reality does not plan well.