I played since vanilla and quit mid-way through Cataclysm. I skipped MoP for the most part and began playing again in WoD just a couple of months before Legion. I found my decision to skip MoP and WoD justified, and fell in love again with Legion which felt like the perfect end to the series; once you defeat Sargeras, that should pretty much be it for the story.
But no, they'd promised a fourth war so they--failed to deliver. Battle for Azeroth, the highly anticipated Fourth War--the singular event that would define the entire series--flopped. It fizzled. It just kinda sucked. As opposed to fighting a fourth war, we end up dealing with Jaina's drama, Baine's drama, Sylvanas' drama, Anduin's drama, and everyone's drama. The zone assaults and war fronts felt forced and like merest training for something better to come that never materialized. Moreover, the lore retcons and rescripts are stupid.
I kept my account active for several months, mainly because my WoW account was also tied to my WoW-Classic account. I played until the madness/corruption gear appeared and then I decided I'd had enough and cancelled my account. I gave up on WoW just before Shadowlands and have no desire to return. This was the deal breaker.