A culture of makework can be harmful in that it would push some people to do pointless jobs when they might actually do something beneficial for society (but perhaps not profit-generating) if they were given free time.
For example, I am fortunate to work remotely in a job that pays me a lot of money, but I am in a country with low cost of living. That means I only work 2–3 days a week. All the rest of my time I am busy with obsessively editing OpenStreetMap, writing the occasional journal publication in the field I trained in at university, and participating in the local arts scene as an audience or writer. I know that if I got to receive UBI, I would still be doing things with my time that are overall contributing to society. Please don’t make me sit in an elevator all day to press buttons instead.
I would like to think we will. I suspect we'll have people doing 60 hora a week of breaking rocks for no reason other than making those higher up the food chain think they aren't hetting a free ride.
Of course while people vote against their best interests (the false belief that hard work guarantees success) I'm sure that those with the power will continue to exploit those without.