If housing, healthcare, education, clothing, and food were free, and I still had income, I could spend it on fitness trainers, life coaches, interior designers, personal shoppers, performance artists, geanealogists, ...
There are a lot of potential mass-market service industries that don't exist because all the benefits of productivity growth (and slightly more than all, now) go to the top 0.1%.
There are still plenty of potential jobs - jobs that we will never have because of inequality.
And we should keep the eusocial aspects of jobs in mind. They provide life structure, self respect, and respectability in the eyes of others as well as a means of subsistence.
Edit: I would love to live in a world where tens of thousands of people have "street party organizer" as their job.