This is already possible today. You don't need driverless cars to do it. Uber can already do it, but it's not taking over. Unless you're suggesting we will have more cars just sitting around waiting for rides, because they're driverless. Then we get back to them being so convenient that nobody will want to ride with another person.
In other words, why does making the car driverless suddenly make everybody want to use it?
So they if get rid of the drivers they contract who is buying and paying for the cars and maintenance? - are you suggesting Uber start carjacking their existing drivers?
Do you know what percentage of driver compensation effectively goes to car ownership and maintenance?
In other words, why does making the car driverless suddenly make everybody want to use it?