Same reason people have hobbies… they like doing things.

What your concern really should be is, who would work for an asshole like you when they don’t have to. The answer is they won’t, get fucked.

Maybe you’d like to explain who and why people would choose to work when they entirely don’t have to?

Two reasons:

1. UBI provides a baseline level of income to keep people out of poverty. But people tend to want more than just the basics, and deciding to work provides additional income for luxuries.
2. People, in general, are inherently motivated to create, and will do so without the threat of death on the streets. Meaning people will still voluntarily work, only they will do so on their terms.

But also, with the increasing levels of automation possible, human labour is needed less and less to fulfil our needs. We need to decouple being able to live from employment. Because the path we are currently on involves artificially increasing consumption and creating meaningless jobs to justify paying people enough money to live.