Aha, hand over hand, now I get to wax poetic about that.

Hand over hand steering was useful up until maybe the mid 1960s. Later, too, but after about 1967, power steering was becoming more the norm. Cars were far more likely to not have power steering. Instead, they employed lower range steering gear boxes and giant trash can lid steering wheels. In order to make a regular old 90 degree turn, you'd have to crank the wheel over way more than you do on a modern car, and the car was heavier, had steel wheels (more mass to move).

They continue to teach it today, because if your car loses power and/or shuts off (ICE cars especially, not impossible with EVs) or the power steering otherwise fails while you're moving, you're really going to want to know how to hand over hand steer. It's much more difficult to steer a car with power steering that's dead/broken than a car that just doesn't have power steering at all. Why they still demand it for drivers' tests on every turn, I don't know. You should be able to demonstrate that you can do it, but hand over hand steering on essentially every car today is more clumsy, as long as everything is working properly.

e:

If you mime driving a car, do you put your hands at 10 and 2? No, you'll probably do 9 and 3.

Only if that's the standard you were taught, and the cars that you learned to drive were ones where that made more sense. I mean, just look where Toonces puts his paws.