Could be that startrek uses a more realistic version of UBI. Everyone is provided enough for a house, healthcare, a few basic luxuries and a hobby, but if you want more than that (say money for an expensive hobby or to go on vacation to the party planet ragealon 6) you gotta work.
Are you guys intentionally ignoring replicators? You don’t need money. You could replicate a whole ship if you wanted to. Your house would be replicated. Same with any hobbies or luxuries, which wouldn’t be luxuries because there is no such thing in post scarcity, you’d just replicate what you want.
Everyone in the Trek universe just does things if they like to do it. Some people like serving people. Other people like to pilot ships. I’m sure the more desirable jobs are more competitive but the only incentives are really going to be the value others see in your work. So someone like Sisko the Elder has people who work for him because they know he is a renowned chef and they want to absorb his knowledge.
