It's quite possible that when automomous vehicle operations start working, the big players will be car rental companies. It's a natural extension to their business.
One set of businesses here has modern engineering practices and the other set are dinosaurs. Furthermore, rental companies have more employees dedicated to sales than to fleet management and their entire current customer base is rental car consumers. They literally need to redirect money to R&D long term where that R&D serves no benefit to their current customer base. Wall Street will punish the stock of rental car companies short term for spending R&D on becoming ridesharing businesses that serve a customer they don't yet even have mindshare with. With the TNCs however, wall street won't see any problem with them building out their own fleet. The only condition where wall street looks down on the idea of own fleet management is if they believe a franchise model with third party fleet managers make sense. Either way the TNCs own the relationship with the customer and therefore has all the power.
Cars can be leased, reducing capex, and maintenance can be handled by specialised companies.
Overall it seems that this upside far outweighs the downside.
I get my car to drive to me to work and then it goes out and operates like a taxi while I'm working. I'd be worried it comes back damaged or vomit all over the place.
No thanks.