The way I remember it working back in the 80s was that cantrips were simple, innocuous little magics one could cast at any time and at no cost, but there weren't any available that did some actual damage during combat. If the game went back to such a model, wouldn't many of the complaints about overpowered casters kind of go away? Because in this case the martial classes really would be needed. Or am I misremembering this and damage-dealing cantrips were in there right from 1e??? I just don't recall ever seeing them, you know?