I am going to ask you to stay awhile and listen.
It never really bothered me before I left, more like “oh, okay, that happened” and just kept playing which back then I was a hardcore grinder that was not above watching paint dry. I spent something like 6-8 months in Cataclysm digging in the dirt to level up archaelogy, played chess with Medivh every week for a chance to get Gorehowl, and farmed old content for rare drops.
Though, and this is my take on it, but the tacking on catch up mechanics was one of the many things that had caused the downward spiral that WoW has been struggling against (along with corporate greed) where in addition to those features level up boosts, 6 month bonus purchases, and other incentives to sort to bum rush content have steadily appeared over the years. Also today’s mindset of “I need it now!” has not helped.
Back in old WoW up until about…I’d say about Cataclysm, you did not get anywhere fast. It took lots of time to get anywhere, and you couldn’t fight entire swaths of enemies. Think of old WoW like going against experienced players in HotS of equal or greater skill than you. You can comfortably or struggle against one player, but if you draw the attention of more than one–or wrong hero–or Nexus forbid drew an Elite (grand master playing a hero you cannot deal with at all) sucks to be you because you are respawning.
Quests took forever (you also did not level up fast at all), raids required a spread sheet and organization on par of a football coach as well as a weekly schedule that you better not breach. Current dungeons required a lot of thought. Everything required a lot of time and energy to accomplish. Professions were just as time consuming as leveling as gathering resources required you to get out there and get them yourself. Unless you had the in game currency to buy them off the market that is, and back then not many people were walking banks leveling up.
If you got to end game content before the next expansion pack you basically had a second job playing WoW. If you got all geared up from Heroic Raids you were in the small minority. You were a god amongst peasants. Fel, just getting into a raid group back then was not easy. Getting everything done in an expansion pack, or vanilla, was about as much of a time killer as a Fallout or Elder Scrolls game.
Then they started making it easier and easier each expansion pack–during them as well–until everyone in HotS terms went from playing in League against highly skilled teams who would delete you if you screw up to playing against A.I…with the bot difficulty steadily dropping.
What this resulted in is people sitting around twiddling their thumbs waiting for the next content drop, even if those people such as myself who sat in front of nearly every wall to watch the paint dry. The one thing that did get harder was getting flying mounts due to the introduction of journeyman quests. But I never did them. I enjoyed running everywhere exploring even if there was nothing of importance.
I feel this is why so many people wind up just leaving WoW for long periods of time. The content is both not difficult (save for extremely tedious bits such as the one dungeons in Legion) while also not taking long to accomplish. Dailies slow people down, but that just has people logging on a couple times a week, and they do not take long to finish so…eh. Warlords of Draenor gets flak for the faction hubs where you had followers that did everything for you to the point people started calling it Farmville. They expanded upon it in Legion. Though even those daily/weekly blocks become negated with catch up stuff. The content simply became less time consuming to finish with less involvement from the players to get stuff done. It was actually counterproductive going out in the world and doing it yourself instead of sending your army of minions to do it for you while you did something else.
The ever expanding cash shop also does not help. You can just buy levels, though it does not give any amount of gratification, and is an instant reward without any work. For me my greatest achievement in WoW was getting the reins of Invincible off of the Lich King after 88 attempts to get it to drop. Runner up–would have surpassed if I finished it–was working towards the legendary quest to get Shadowmourne, but I both lost interest and could not get anyone to help me at the time.
They’ve also released some really dumb stuff that had no impact on player retention at all. One such item was the S.E.L.F.I.E camera that lets…ughhh…you can take selfies with in game. I am not making that up.
Throw in some really dumb story decisions and, well, that is current WoW right now; struggling to keep players. The game went from being a time sink to a Facebook game, though from what I have heard Dragonflight was alright, though I do not know if it still suffered previous expansion pack problems of letting players zoom through content.