They should make a WoW 2. New engine, same size as a current expansion, new characters, world and lore. Still do Alliance/Horde so there is an over-arching war. Make the story more immersive and involved. Stop treating the player character like THE hero, and more like A hero. I feel there is a lot they could do but they are joined at the hip to a dried husk on life support with the current model of the game.
The story has only gotten more immersive and involved over time. Your opinion is fine, but it reads like someone who is critical of modern wow without playing modern wow. There are bits of lore that treat you the same as everyone else (storytelling aspects almost dictate that in things like scenario instanced bits of the game for example). But the game has never treated you as "the hero" - the players are heroes that band together. It makes far more sense to acknowledge your power than it does to pretend the players are literal scrubs like vanilla did pretty often.
Vanilla - game acts like you're the same as anyone else, while you're murdering Kel'Thuzad and old god C'thun....k
TBC - game still treats you like a scrub despite you going and doing stuff like reviving the sunwell and beating back Kil'jaeden. Some dialogue and scripts during the raids themselves tends to make you sound powerful, but the rest of the game ignores that.
Wrath - This is where they started calling you hero and champion and such, you still do a lot of menialshit but where appropriate they treat you like you're not a bullshit rando. Note, a hero and a champion are not THE HERO or THE CHAMPION. You are part of Tirion's army of light and bring Arthas' reign to an end. Tirion still is the main character and does the final deed, but you support him in it.
Cataclysm - Same deal as wrath, you're a hero or a champion, major characters from WC3 now know your name and acknowledge your contributions, you help Thrall and the dragon Aspects end Deathwing and the dragon soul.
This is basically how it's continued since then. Yes, for the purposes of like, your garrison or your class hall for example, it's YOURS and everyone has their own that is 'theirs', but the game never says "Oh you're baby jesus" - that's thrall, instead you're part of the powerful army that represents the best of what azeroth has to offer. It would be patently ridiculous not to refer to players in this way in some fashion, we literally do every major feat of strength the planet has to offer.