Problem is the more systems and warnings you pack into a plane, the more likely one of them will malfunction and work against you. Or the software can be sabotaged/hacked. An insane pilot is extremely extremely rare but computer failure is common.
For that reason every airliner can always revert to full manual mode and each of the hand controls are multiple redundant. Giving the pilot full control to respond to mechanical failure is more important than keeping control from a potentially crazy pilot
Cars have sensors which stop them from backing into a wall. Not sure why planes couldn’t feature something similar to avoid flying into mountains.
Last I checked, cars were not overriding the drivers on highways.