The Internet ate my well crafted response, so I'll just sum it up here:
You can't be a mundane hero in a game where 80% of your allies and enemies are not mundane. Eventually, you fall behind. And when you do, you start to rely on magic as a crutch. There is functionally little difference with a fighter who has a flame tongue sword, adamantine armor, and boots of flying and a dragon knight who has hardened scales, coats his blade in dragonfire, and manifests wings except the former was gotten out of a box of DM charity and the latter is a part of the characters identity and abilities. There is no mundane fighter, only one who gets his power in loot boxes.
I'd rather that power be part of the class and since weakening casters is out of the question, let's give the warrior classes what they need to survive. And if that means all farmboys end up the heirs to a mystic tradition of magic knights, I can live with that.