A driver who rents pays every week for as long as he works. He carries the bad week, the slow month and the blame for a scratch. After three years of that, he owns exactly what he started with.
The vehicle is the only asset in the arrangement, and it belongs to someone else. That's why a driver switches platforms for a slightly better rate, treats the car as somebody else's problem, and leaves the trade the moment a steadier job appears.
Change who owns the vehicle at the end and every one of those behaviours changes with it. That's the whole idea. Everything else on this page exists to make it work commercially.