What exact type of input is being grabbed by these screens? "Critical pilot systems"? Touchscreens already exist in airliners, for systems used by crew and passengers, but that's beside the point.
Not saying it's right or wrong but your original post is 100% incorrect.
Many recreational pilots fly with uncertified gear (GPS in particular), and even regular smartphone/tablet apps. They also have the required paper documentation and certified instrument but that's just to cover themselves, and as a backup.
Also, some airlines now have officially certified iPads as EFBs, meaning pilots no longer need to carry paper backups.
I also imagine that there are other reasons for both airliners and cars to replace buttons with touchscreens, namely that of cost instead of prioritizing safety and stability, and in general I am not a fan of that trade-off. But I'm also not claiming to be representative of the automobile market in general.
It's not just Boeing, who you accused of being backwards who are doing this, Airbus is too, along with every other manufacturer. Garmin and BendixKing now offer touch screens and it's clearly the future of GA as well not just commercial aviation.
Everyone believes that this will increase safety. That showing only the relevant information in a tunable and interactive way will decrease distractions and help focus on what matters.
The idea that this is to save money is totally absurd! A 777X is $350 million dollars. Any accident would cost an astronomical amount compared to the cost of switches. Even leaving that aside. The touchscreens are actually far more expensive than the old instruments.
This is just a way for Honda to cover up the fact that they can't write software, can't design a reasonable UX, don't want to spend money on it, and want to live as if it's 1999 forever.
Furthermore, tactile feedback is safety. The fact that each switch has a feel, a size, a position - that let's your brain know what you are doing without having to take eyes off the road.
Still, if you’re borrowing your wife’s car it’s easy to realize you don’t have great blindspot visibility at which point looking at a touch screen is very distracting.