Or at least do no harm. Like, I don't understand who's against this, or why it hasn't happened. Classes like fighter and barbarian that just run up and take the attack action over and over, sometimes attaching small bonus effects, have people who love them. They love them! There's absolutely no need to make them more complex, given that there are people who enjoy barbarian as a basic thug who should be allowed to keep the class exactly as they already enjoy it.
But like... if you added a couple of classes that did get a bunch of choices, that played like a skilled swordmaster spending their turns going "hmm should I try dazing that group with Blade Dance or have Blind with Rage get the big one flailing around at his buddies?", doesn't that benefit everyone?
No classes work like that, so it's not stepping on any toes, and now people who want to play the very common fictional archetype of skilled, technique based combatant without having to be a spellcaster can do so. Existing martials stay exactly as they are for those who enjoy them AS-IS. Seems like the obvious solution? That's not to say WotC will do it, they seem creatively pretty bankrupt these days, but it seems strange that there's so much confusion about this.