For me it is clear that the current development team destroyed world of warcraft over the years.
Instead of focusing on the world, they moved all their effort to (competetive) endgame. They forgot about the world they created in classic, and left it unchanged for a very long time until cataclysm, where they renewed it in a way people did not like much as well.
Nowadays, if a new expac releases, all the focus is on new raids, mythic dungeons and rated pvp. Questing content is more a chore than a main feature, while it should be the core gameplay. It should be about the world mainly, and about dungeons and raids only if there is any time left to create them.
I believe the classic reboot was successfull at start, because all of the world mattered again. In nowadays World of Warcraft, the world does not matter at all, and the fun gameplay happens in instanced content only. Leveling is a chore, without any kind of challenge. Crafting in old content does not matter. Crafting at end level feels like a raiding extension, as you need mats from raids to get raid level gear. Beside that, crafting is just another chore, as like are world quests.
Endgame feels like a massive collection of time gates, where you cannot decide yourself what you want to play. Patch 8.3 shows that really well, where you have to do both assaults and world quests, which lack of fun gameplay or any kind of engagement. While the Nyalotha raid received all developer attention.
For me it is clear that Ion Hazzikostas, as game director, is directly responsible for how the game evolved. I think he should be replaced by someone who actually knows how to design a MMORPG with a living and breathing world, which does not want to be a dungeon crawler.