Hot take: remove the Fighter class. Seriously, it's identity is "fighter" when everyone can fight pretty much equally in 5e. There's really very little distinct or flavorful about them compared to other classes; Paladins have magic and auras and lay on hands and big boom smites. Rangers have spells and hunter's mark and options the fighter can only dream of (I mean, the lowly Hunter gets Whirlwind Attack, something the Fighter can never have?). The Barbarian has savage attacking and RAGE!
All of the Fighter's flavor comes from subclasses....and some of them even fail to be all that interesting. You can't be a weapon master, because anyone with proficiency is just as good as you. There is no weapon specialization, really. Heck, with the loss of GWM, Fighter damage is going to fall into the basement.
So yeah. Replace the Fighter with flavorful classes. Give us Myrmidons, Gladiators, Swordsages, and Warlords!