I don't think that's a good analogy (to be fair, almost no analogies are, especially not the terrible ones I make!).
In D&D, if anything, the "pedals and dash" and so on are the rules, classes, and so on. Those remain consistent.
The setting is the place you're driving that car in. And yeah, sometimes it'll be open autobahns and modern cities with clear traffic signals, but sometimes it'll be dirt roads which aren't on the map, or driving on the wrong side or whatever.
It was ever thus, too, well certainly from 2E onwards. You can't make many assumptions - most settings will challenge a lot of them. Some will destroy all of them, like Dark Sun did. And that's 29 years ago.
Exactly. It's not exactly a hard thing to manage.
I mean, I've run dozens of different settings over the years. I've literally never had someone's mind be blown because a bunch of creatures didn't have the expected behaviour for them from a corebook.