I chose "One of the worst WoW expansions ever", mostly because it's hard to judge. Cata was the first bad expansion I experienced, and honestly, my case is peculiar, as I quit because of the community within the first month. Running heroics the first week with people being used to WotLK heroics just broke me. Not because of the expansion itself. So I can't really judge that expansion if it's worse than BFA. WoD I played a bit more, a couple of months or so, but the whole loop around the garrison and everything felt terrible. Felt far too busy, wanting me to always keep things running in the garrison as well and the whole AU thing was stupid. So I ended up quitting that expansion as well. BFA I played about as much as WoD, though I played WoD in concurrent months, while BFA was played only the first month and a month after two of the patches where new reputations were released.
To me, BFA feels like the worst, but then again, I've not played through all of WoD or Cata in its time, so it's hard to judge if it's the worst. My classes for sure feel terrible, Azerite just sucks, IEs are a chore, warfronts hahaha, world quests are a plague, war mode is terrible imo as a PvP server player, professions still completely broken, story is awful coming from the promise it showed before release, leveling experience wasn't as good as previous expansions and the world doesn't really feel as interesting as previous expansions. Only good thing I can say is that art looks good and raids have been okay/good. Oh and more trolls is always good. So yeah, I personally feel it's the worst, but to account for the weaknesses of my own judgement, I feel it certainly belongs in "one of the worst expansions".