That would make sense if Zillow employees were literally the people painting the walls. As it is (or was), there's probably a project manager that managed hundreds of houses, spends all day on the phone call painting companies, and then just assumes they do a good job. I'm perfectly capable of calling a painting company myself and don't need to pay Zillow thousands of dollars extra to do it for me.

The integration of renovation in the sales process is a differentiating factor in itself. That you're not the target market or, that it might not have been successful, doesn't change that.