And roads, and other auto-friendly (or auto-dependent) infrastructure and urban / national land-use.

Cars went from a luxury to a necessity, though largely not until after WWII in the US, and somewhat later in other parts of the world.

There remain areas where a car is not required, or even a burden. NYC, and a few major metropolitan regions, as well as poorer parts of the world (though motorcycles and mopeds are often prevalent there).