"Hey, I want to play WoW. What class should I play?"
"Well, what do you want to do?"
"I enjoy healing."
"You should definatly go Priest then. They not only have 1`, but 2 healing specs! It's meant for you!"
Fast forward to today. We have 1 spec called Disc. It's literally the least traditional healer ever existing outside Fistweaver monk (they have traditional healing a viable option though). OK, Fine. Seems like several people enjoy this DPS for healing style. Fine.
Then where does that leave the people that just want to be a traditional healer? Of course, Holy Priest. It's fairly straight forward, outside the Holy Word mechanic, and fits the traditional healing role fine. However...
Holy is just completely unviable in anything outside raiding. Want to Quest? They are the slowest. Want to do BGs? They are the weakest. Want to do 3v3? They are unviable, why the heck are you not Disc??? Want to do M+? No, you are not invited.
Honestly, if you want to play a traditional healer these days, you better reroll a Resto Shaman..
How come the Holy Priest, the traditional healer, is unviable for healing in most scenarios?
There is absolutly nothing changing about Holy Priest in Shadowlands.
If you reply Holy is fine, do you play Holy? And what content do you do?