I think they just ran out of ideas. I mean, where do you go after killing planet destroying titans, intergalactic legions, old gods, new gods and everything else in between? You reset the world so that it’s meaningful (again), which it will never be. Someone should read Kierkegaard XD
The story of wow is fairly straightforward but has an obvious ending by how it was setup: You start the story in wc1 and wc2, orcs bad, humans good, fight! Build around it, get to WC3+FT where you really flesh out the world, the peoples, the factions etc. You could consider this the ‘ancient history’ of the game (prehistory is obviously just D&D). World of Warcraft is the cannon interpretation and resolution of ancient history → establishing of the factions, worldbuilding in the true sense and eventual defeat of every single canonical villain that was set up in ancient history.
Up until and including legion, you were literally fighting the enemies of legend, come back for one final showdown. You were the hero, the one who stood against the ancient enemy, the one who would finally prevail, once and for all and free this world from danger. Of course it felt epic. World of Warcraft ended in Legion. You were never more canonically powerful than in that expansion. Afterwards, World of Warcraft just became a corporate cashgrab and mmo experimental theme park.
BFA tried to recapture the shine of discovery and the origins of the Horde and Alliance by meeting new peoples and slowly integrating them as new races within the political organizations that are now the Horde and Alliance. A call to the old days, but with the slick new ways of the new world. Legion needed to leave behind a new villain, a trace of evil of some kind and Sylv was obviously an easy target, which then manifested in BFA and SL. SL is obviously (for me) a love letter to TBC, that moment when Blizzard were like, let’s try to be epic! But SL was a super controversial expansion both in game and outside; the math nerds had taken control of the game and you needed to be one to play, which was not fun. Exploring the greater realms of reality is indeed a step up from fighting intergalactic legions, but a bit to high minded for many people who just do not care for this game’s worldbuilding. It was epic in its own way, but an epic looking car that is too complicated to drive doesn’t really feel epic, it only kind of looks epic, which sucks. Unfortunately, SL, the pandemic and the lawsuits taught blizzard one valuable lesson: being epic doesn’t pay; people do.
As such, the atrocities known as TWW and it’s predecessor DF were born. DF was a timid attempt to make an expansion that setup other expansions, systems and features; in a way it was cataclysm all over again in the worst ways. Directionless and just a cutesy budy budy family picnic like expansion, DF will probably be many people’s first time playing WoW and they will expect the game to be more like that in the future and it shows. TWW is just DF all over again with literally everything that made wow feel epic completely stripped away, a Cataclysm’s Cataclysm where they are trying to reset again for the World Soul Saga. Is WoW so silly it takes 3 expansions to course correct? Will it finally become more epic in Midnight when we go back to Icecrown or maybe in the Last Titan in 4-6 f-in years when we get Silvermoon back? Are we going to get some epic plottwists after this next story filler patch? Doubtful.