Right, but Uber is not cheaper than owning and using one's own car, so they haven't actually lowered the cost of a car trip, only of a taxi trip. Own cars are not only still much cheaper, as the cost per trip actually goes down as you use it more, making Uber even less attractive as the number of trips increases.
It's exactly for people who take very few car trips, like me, since they use mostly public transport, that Uber is actually more attractive than car ownership, since it avoids the fixed costs.
As for road repair costs, that's usually paid off from gas taxes, which Uber pays linearly according to their used miles, so it's not "socialized" in any meaningful way.
