Obryn
Hero
You know I responded directly to much of this in the parts of my post you cut, right?I think that MM actually brought it up in a recent article, but Fighters have always the baseline that every other class differentiates itself against. Rogues sacrifice armor and hit points in exchange for their special skills, wizards sacrifice all that and their weapons in exchange for a handful of spells, clerics sacrifice smaller amounts of weapons and attack bonus in exchange for less-useful divine magic.
But the Fighter doesn't have anything unique. It's just better at everything that everyone can do. That's what the Fighter was in every edition prior to the (incredibly controversial) Fourth Edition.
A level 10 Wizard or a level 8 Cleric might be just as good at fighting as a level 5 Fighter, but for any given level, a Fighter of that level will be the best at fighting.

"Even if that's true - and it's largely not, except arguably for 3e - it's inadequate." And even in 3e, there was a realization it was inadequate, and Bo9S - a game-changer of a supplement if there ever was one - was introduced.
There needs to be a baseline when you're making classes in order to try and balance them, but there's no functional utility in that baseline actually being a playable class. I am saying the same metric I posted above should be true for the fighter - a Cleric 10 should never be able to fight the same way as a Fighter 3, any more than a Fighter 10 can cast more Cleric spells than a Cleric 3.