The game’s hardest difficulty should be heroic level of difficult. That should also be the ONLY difficulty. You’ll have half the players progressing on it all patch (because they were normal raiders before and this will be a struggle) and the other half will clear it faster. The RWF will be over in a single reset, (healthier for the players anyway tbh…)
Mythic+ should have all gear rewards completely removed, it should be a cosmetic hard mode only like in MoP.
Rated pvp should be limited to RBG’s, arena should be a “for fun” wargames mode to challenge your friends and goof around. (seriously, nobody plays arena anymore, its dog water).
New dungeons should be introduced in each patch, and the number of dungeons on launch (along with zones and raids) should be what makes the most sense, not just 8 and 4 and 1 respectively as we have now.
Reforging should be reintroduced into the game. Tier sets should be kept around. Aoe cap completely removed on ALL ABILITIES THAT DO AOE.
And here is a really important one. VISUAL CLARITY ON BOSS ABILITIES SHOULD BE IMPROVED DRAMATICALLY. FF14 beats WoW in this 100 times over. Seriously in Nathria we had red swirlies and red lines overlapping on a red floor with red lighting…
Legendaries should be extremely rare item drops and they should be weapon only. Armor legendaries are boring as hell.
HP scaling on zones should be removed completely. Zones should go back to being level banded like in Vanilla-wrath where you progressed from one zone to the next and the mobs were always the same HP regardless of the players Ilvl.
If world quests and dailies are going to stay in the game, they need to be as easy to complete and as quick as legion WQ’s were. I should be able to fly down, aoe it all down, and fly away in 3 seconds for each WQ. They are busy work content AT BEST and the rewards are far too weak to take as long as they do even in mythic gear.
The crest/flightstone system is a neat idea, but flightstones need to be FAR MORE OBTAINABLE. Why am I always out of flightstones but loaded on crests? It should be the other way around, or just remove flightstones entirely and just do crests.
Add player housing into the game like in FF14. Make it instanced but completely cosmetic in nature, no player power or gold farming involved like in the garrisons.
Class halls and class quests reintroduced into the game, best content in legion bar none.
PvP damage should no longer be calculated differently than what your client is showing you. Obliterate should not hit for 1.5k when it says 15k on my screen, and vice versa. Clarity of information is key.
Any unobtainable item in the game should no longer be unobtainable. Anybody who wants to join wow now and become a collector is starting off unable to ever fully complete the game.
The story should stop focusing on large lore characters and the drama around them. Legion and WoD make WAY more sense because the story is a big bad, (iron horde/legion) and all of the lore characters are in and around the threat but never the true focus. (shadowlands and BfA were literally just the sylvanas expansions, it’s super boring).
New zones should STOP BEING ALL MOUNTAINS AND MAZE LIKE PATHWAYS DESIGNED TO TICK OFF PLAYERS UNTIL THEY CAN RE-GET FLYING FOR THE 10TH TIME. Ok yeah that might just be my bias but the zones are all just hyper dense mountain ranges, and flying should just be something we get at max level for a gold sink and that’s it, no achievements, and no quests to get it.
Introduce guild order halls, (also instanced like player housing) which is also cosmetic only, (could include things like a guild bank vault inside as well for convenience. Guilds could work for certain objectives to unlock portals in their guild hall to major locations in the game, including but not limited to the newest raid entrance.
Raids from previous expansions should be IMMEDIATELY considered legacy content the moment the new expansion drops, lowering the difficulty and make them one shotable by a single person. (The exception should be the last raid of the previous tier, since it’s gear would still be too strong for leveling for one player to just dunk on.
New system introduced where players can create quests for other players to take on in return for a reward, (like the new crafting order system in dragonflight).
No player-power effecting time gating in the game period. If I miss a day of playing I should not be behind anyone on anything other than gear from dungeons or raids.
And of course zero borrowed power systems ever.
The games tone and themes should change back to more fantasy themes and less sci-fi. Also make the dungeons actually dungeons. I’m tired of open air dungeons, it was fresh in wrath, now it’s not.
TL;DR, make the game for the 90%, not the 10%. Elitists won’t like most of what I’ve said here, but the game shouldn’t be made for them.