Agreed, which is why I propose to cut down the filler and make raids only when they align with a major shake-up in the story and significant story development.
That is why I mentioned Aberrus. What storyline development did Aberrus have? It and its final boss are literal Nobodies that didn't impact the story in any meaningful way. They couldn't even be bothered to make an actual end cinematic for Sarkareth's defeat, the definition of filler.
MoP did that twice. Yes, MoP, the beloved and nostalgic expansion of many people, the peak of 2010s WoW according to many people.
https://warcraft.wiki.gg/wiki/Patch_5.1.0
https://warcraft.wiki.gg/wiki/Patch_5.3.0
MoP had four patches, but only two of them added Raids (and those two Raids were sprawling and huge). The other two patches pushed forward the storyline simply by adding new questlines (very long questlines with significant developments in the old world, as for instance the Revamped Barrens in 5.3) and new Scenarios.
Those expansions did not have Mythic+ and Delves.
What I'm saying is: Now that PvE endgame is not just Raiding anymore, why the "Middle" part needs to be a raid, instead of a new megadungeon and new Delves?
I will finish by saying that I would gladly and happily sacrifice Aberrus to get Housing.