Also it’s an arms race. They feel safer because they’re comparatively above smaller cars, but then when everyone is riding tall trucks that additional feeling of safety becomes moot as you no longer have the additional height/visibility over everyone else.
And conversely, the reason they feel less safe in smaller cars is because of the comparison to larger cars on the road. They aren’t solving anything in a larger vehicle, they’re just perpetuating onto others what gave them small-vehicle anxiety in the first place.