Mostly that isn't needed because the controls you need are generally obvious. Every car has accelerator and brake pedals (some also have a clutch) in the same position that works the same with no need to look. Likewise they all have a steering wheel in the same position that again works the same as every other car.
They have turn signal indicator that works the same. Most cars it is a lever off the side of the steering wheel. One car I drove (at night) instead had a switch on the dashboard - I successfully used this to signal my turn several times before I realized it wasn't a lever - but it worked like one so it didn't matter.
Because car makers have historically been good at doing consistent UIs like this when I get into a rental car the only think I need to figure out is where the key goes and how the transmission shifts (shift levers can be many different places and have many different patterns). Everything else important to driving is the same on all cars.
Things like the radio and climate system are not the same on all cars. However they are not critical to driving.
I don't agree with this logic.
When you rent a car it's common sense to familiarise yourself with the controls before you start driving it.