I recently came to that realization after just letting my sub run out and played something else.
WoW is not a game because 90% (or more?) of the activities do not offer the slightest amount of challenge at all. Your character pretty much is immortal in open world content, you press your few buttons to kill a mob, or 5 or 10, rinse and repeat to reach X of Y or to fill up a bar. That makes levellling more of sequence of cutscenes and NPC doing things with some button pressing in between. A video "game" for me is "playing", that means reaction, hand eye coordination, getting used to AI patters and appropriate reactions to them. At the beginning you fail, the longer you play the better you become, in the end you master the challenge and move on (either to next difficulty or you pick another game).
So what about instanced content, i.e. raiding? normal difficulty no challenge at all, even if individuals fail to deal numbers or to not stand in fire, in the end your raid group as a whole will balance that out. Being bad at the game has no other consequence than having to wait for the others to complete the encounter.
HC raiding is where the earliest kind of challenge comes into play, but as its grouped content, indiviual failings again can and will be balanced out by others individual skill. Apart from that, in a real game you can just keep on training by repetition as often as you want. But you cannot train a HC raid encounter as you can train a rogue-like run. You need to wait for raid night, when you got a good group you can faceroll through encounters without your individual perfomance mattering. So to actually become a better -player- it required a bad group that enabled you to repeat the gameplay as often as its required to master it eventually. But again, this only once per week.
If you want to "play" the game (meaning learning gameplay patterns and success wherei failed before) using LFR (leave out nuisance like toxic players and leavers) you have to wait 30-60 mins as a DPS, so thats not really an option.
I realized WoW is nothing else than a way to spend/waste lifetime. Everything is kind of pointless, loot is pointless, character strength is pointless, your skill is pointless because it's either not required at all, or required at a level you cannot reach because you cannot train into it. So you what you actually need to do in WoW to have some challenge is go through all those not challening activities, socialize with people for scheduled activities and those people need to have an average skill level of yourselfs one, to neither get carried nor others being an obstacle for your skill progression and success.
After i realized all this i lost all interest in Shadowlands, as now i always have the idea in mind i am not playing a video game here. I just press und click buttons without any feeling of pride and accomplishment. It's entertainining yes, at least the first time you see some content, but it's not "playing" as i understand the term.
Quite a bummer for me actually, WoW was my favorite and only game for a very long time and now i realize i should have actually played other "real" games instead.