Cars allow people to travel longer distances more conveniently, access remote areas, transport goods efficiently, and have greater independence in their daily lives. They also enable emergency services to respond quickly, support economic growth by facilitating trade, and provide opportunities for leisure travel that were previously impractical.
They let us do things efficiently. Sure, you could have moved a truckload of goods up the coast using 20 wagons, 40 mules, 20 drivers, 10 security, and a week's time. Today, one dude can move a truckload of goods up the coast same day.
(Numbers have been entirely fabricated, feel free to send adjustments.)
Travel [long distance], relatively safely, in [short time].
LA to NY is a long roadtrip, but you can do it in 2-3 days with a few friends to rotate drivers. Walking that is a months long journey with a very real risk of death if you don't have a support vehicle.
I got yelled at once at the bank in my office's parking lot for going to the drive up ATM instead of going inside to a teller. So they definitely agree with that. Not allowed to walk through a drive through.
I think "carrying something heavy without slavery being involved" is a new capability compared to "enslaving people and making them carry something heavy".