I think somebody coded for “no contact with the smart key in the last 15 minutes“ … which is even more ridiculous because the car could easily be standing at home and never leave the smart key range.

The ECUs in the car wait some time after you close the car before going in sleep mode. It's called "parking mode".

Tesla does the same. Mine stopped working on the highway (it let me get off it though) and on the gas station, this was its v suggested way to reset. But as this was in the dead of night in the freezing winter, I had a lot of doubts before doing this. When a guy with a crane arrived, I finally left the car and was not able to open it again.

This is not true. The Tesla infotainment system can be restarted - even during - by holding both steering wheel buttons for 5 seconds. I've never had a problem with it (I've never had a problem with the infortainment system, I have had other problems with the vehicle) but I've tested this while driving and it does not affect the drivability of the vehicle.

That is true, it was the suggested way by the Tesla hotline after the method that you mention failed. The solution that worked ultimately was the flatbed truck...