Lots of people enjoy working on high skill, fulfilling jobs like inventing things. Few people love working menial labour jobs. AI will probably take the former jobs but leave the latter, which will still need to be done. If everyone gets a decent UBI, how will we allocate these unfulfilling but necessary jobs?

> Also, if you really think every UBI study is fundamentally flawed, feel free to design and run your own.

All temporary studies are fundamentally flawed, because people act based on their permanent lifetime income. It's not like I can design it better, it's just not something that can easily be studied (on any reasonable time scale).