Someone owning a car without using it to generate income, leverage, or opportunity is the definition of unproductive capital rotting in a driveway. The uber for x platforms are market makers, which is about as valuable a service as it gets. The only ones it seems to bother are those who would seek to exploit people politically.
The platforms have pernicious pratices, certainly, but the political outrage about the the gig economy has served mainly to discourage competitors from entering the market to make it better.
I'd argue the critics of the gig economy are ensconcing the very platforms they're complaining about by threatening the market - and they have never solved a problem they didn't first invent by characterizing everything as exploitation from the outset.
This is about par for the course for people who don't solve problems with discovery, technology, or consensus, but rather, invent problems to leverage them politically and add them to the portfolio of things they create rules for and manage. These are not reconcilable world views, but when one is committed to the logic of an idea, I sympathize with how they might interpret inconsistency with it as stupid.