That's not what UBI is about at all. UBI is about getting paid no matter what you do. Which could be doing nothing. Or it could be studying or practicing or learning a new career or even working. The fact that UBI doesn't disincentivize spending ones time in a certain way (whether that's economically productive or not) is hugely important.

This is an aspect of where there's a huge misunderstanding about UBI due to competing economic theories. There are some people, a lot of people, who believe very strongly that the economy is fundamentally coercive. And, more so, that coercive economies are natural, beneficial, and overall desirable. A lot of that thinking has certainly been baked in to a lot of conventional wisdom, culture, laws, and regulation in the economy of western countries for centuries. There are other people who believe that the economy is or at least can be fundamentally cooperative, and more importantly that a cooperative economy is more beneficial and desirable and no less natural than a coercive economy. And this is where UBI comes in, because UBI is essentially how you bootstrap a more cooperative economy. One where people work not because they are coerced to participate in toil due to the alternative being starvation and privation but instead because they enjoy the work or are fairly compensated for it and treated well.