Car seats need to be installed correctly, and adjusted to fit your child, in order to be safe. I assume Uber drivers would need to be taking the seat out of their car and reinstalling frequently, and parents walking up to some random car seat aren't going to know exactly how to adjust it. I suppose this is good if you have no other option, but i'm surprised Uber is willing to accept the risk. Maybe they're just pushing the risk onto their drivers somehow.