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.
My question was what do cars let us do now that we couldn’t before.
We moved heavy objects and traveled long distances long before cars.