If you know ahead of time how to do it. If you are in a new car, discovering which of 12 different switches, knobs, and dials adjusts the wiper speed is somewhat baffling. I always spend 5 minutes in a new rental car trying to memorize how to do this, but if it's been a couple days since I rented the car and I'm trying to do it for the first time, it is not something that I try to attempt to adjust while still on the road.

Sure. But for physical controls it's generally easy to discover as well. Indeed it only takes a few minutes in an unfamiliar car, after which it's easy to use the controls with at most a passing glance.