I'm really curious, was this in on the later expansions? Because Shadowbringers is starting to feel a whole lot like Wrath of the Lich King for me, which is where I can pinpoint that game lost me. It was in the first dungeon, I was playing tank as I had for many years. As I always did before, started putting marks for sap, sheep, kill first, kill second etc. until on of the party members asked me what I was doing. "Marking for cc and kill order" I said. "No no", they replied, "just run in grab everthing and we'll aoe them down." And the catharsis was fun. At first, then it grew stale. It was no suspense nor tension in going into a dungeon, it was gather everything and burn it down, mobs barely posed a threat. Consequently it was also where the I found myself able to solo Elite mobs higher level than me as a Protection Warrior. I tried to just relish in doing damage, but it didn't grab me for long.
I'm with you on the note that just the concept of rotation still feels like an alien concept. I dunno, it's always felt strange to me so I've gravitated towards the mmo classes and jobs that probably can be played optimally, but is instead utility, tools-focused with different kind of approach, preferably right at it's fingertips. Warrior in vanilla WOW above comes to mind, as did Scholar in 2.0 and 3.0 in FFXIV.
Since all of this game's mobs and bosses follow a hard script I just started to get a feel for when it was gonna use what, and planned mitigation accordinly. Just getting the feel for it made Cleric Stance another reactionary skill as I got more and more used to it. Back when I was deadly afraid of the doom Cleric Stance could bring I was still encouraged to just throw out a dot or two if found myself with nothing to do, as everything helps. Using CS just grew on me until it became second nature. Even then the frantic cases where someone took unexpected damage and I still had 3 seconds left on the cooldown at least livend up the samey dungeons.
Today it could be an actual role-skill choice to replace Repose and the Role Quests could be used to teach one about it. First added to bring some color back for when soloing as a healer, then starting to use it dungeons as you get more and more used to them. I can definitly see CS coming back without the Int-damage scaling again as a choice skills, not just part of some rotation.