An infotainment screen can be separate from the thing that handles driving without a need to replace everything with physical buttons. It's just a matter of having 2 computers (and thus extra cost) that are not connected. The driving computer can handle things like ECS, ABS, acceleration, braking, locking, unlocking, headlights, turn signals, and of course managing the motor components all while being disconnected from the Internet. The cabin computer can handle everything else and appear to the user the same as it does today. You can even connect the cabin computer to the Internet without risk of dying if you want the ability to remotely heat or cool the cabin or want an auto emergency response call in cases of a crash.

You don't need an individual control for all the things that happen in a car, you just need intelligent, security aware decisions to be made when deciding what is critical for driving or safety and what is just there for comfort.

Uh.. cars existed for decades without needing hundreds of buttons everywhere. Modern cars are still made without Internet connected infotainment systems.

Your argument doesn't hold water.

The real reason it's not air-gapped is because it makes the package count lower, and manufacturers don't give a shit about owners' privacy or security.

But if you were to have a physical button for every single thing you can adjust in modern cars, you’d literally need over 100 buttons which is absolutely insanely bad design.

How many things are adjustable in modern cars that are actually necessary to adjust? Having that many options is just piss-poor user-interface design. The only things that really need buttons and knobs are the parameters that have to be twiddled with while the car is running. The rest is offline config that could be done just fine with a touchscreen or a mobile app without causing driver distraction and getting people killed. And none of that has anything to do with physically separate data paths for ancillary functions versus critical controls.