I would not be so sure. Avis, in particular, is actively pushing for a flow where you book online, use "secret" promo code to get full insurance for basically zero, pick up car directly on parking lot with keys inside, and drive away. It takes literally 5 minutes and a single employee to check your driving license and contract. Hertz is trying to do same, though less effectively. Their websites and apps are still horrible, and it's perplexing why, but the cost of building decent apps will be immaterial compared to the cost of the vehicles, and from that, building actual on-demand short-term rental network does not seem so unlikely.