I very much agree with you, and would like to add that flatness in phones is a feature because today phones are pocket computers, and computers should be able to provide any arbitrary UI to function as such. Cars on the other hand are not a computer nor are they intended to function as one.
The fact that modern cars expose part of their on-board computer to the driver is no excuse to treat any capability that may be handled by said computer as something exclusively accessible via a touchscreen UI, especially when its something that is expected to be interacted with while driving (audio playback control, climate control, windscreen wipers, etc.). A touchscreen is fine for features that should not be done while driving and did not exist or were not easily accessible prior to the ubiquity of touchscreens in cars. For all intents and purposes those are computer features. However, subjecting anything that was previously available via mechanical interaction to it is an unacceptable regression.
4.5th and 5th gen aircraft are touchscreen though, with full tiling window managers. They're still highly classified, so we're unlikely to get any more info on them until the 6th gen in the 2030s.
Haptic feedback is a core part of how humans process the world, and to remove it in favor of more frequent updates seems like a naive decision at best.
Flatness in phones works because we can use our full attention - which is also why car accidents happen when people use it while driving.