Since blizzard began the Voidform route with shadow going into Legion, it changed on a fundamental level everything about Shadow in its toolkit and spells and flipped the entire spec on its head.
Shortly after, the developer left be it quit or let go I’m not sure.
Since then, every time shadow has been in the stage of major development, the wow dev in charge left during the development cycle.
This happened midway in BFA I think?
During Shadowlands Beta
And beginning of Dragonflight beta.
So we end up getting half designed and only half baked ideas are implemented before it’s pencils down as it’s time to ship the game.
So essentially, Shadow has been in development hell since the beginning of Legion.
Voidform at its core only excelled in long form and stationary fights. So basically raiding and at high level M+ they got by.
But in PvP, low 5 mans or low level mythic 5 mans and world content be it leveling or max was downright atrocious when you were forced to play with Voidform when it automatically put you into Voidform outside your control.
What typically happens is by the time you build up enough insanity to go into Voidform, it triggers right when the mobs are dead or nearly dead and thus you waste you powered up state moving to the next group of mobs.
Since the Powered up state of Voidform was essentially infinitely scaling, it caused to it base form to be infinitely weaker thus causing you a lot longer time to get anything done. This is why short form content or PvP was awful when dealing with Voidform.
Since then, they made small steps at a time to improve it the way Voidform works and add Dark Ascension (Cataclysm version of Dark Archangel) back allows it to be a bit more predictable yes but also actually effective and not useless the majority of the time.
But with so many conflicting and overlapping spells, shadow has found itself in a state of limbo where devs can’t seem to figure out the best direction to take shadow in as it seems anyone with enough shadow knowledge to speak on it leaves the company.
The result is what we have at the current day where there are the foundations of good ideas, but not enough time and effort to make them fully realized.
Shadow seems to also be plagued by a double standard of design philosophy as many reasons given to hold back at giving shadow what many main shadow priest players have requested has been met with a NO followed by reasons ranging from other classes have it already or it impacts PvP in a way they don’t like, like not giving Spectral Guise back (short duration stealth we had in MoP and WoD) because it makes the enemy target frames disappear? Which apparently is enough justification somehow?
Or not getting a displacement ability like Reverse Leap of Faith (we had in shadowlands) or Door of Shadows (had in shadowlands) because at least with Leap of Faith, most people would pick the self displacement version and they didn’t want that to happen.
But then they also gave hunters a group leech ability I think? And mage a group damage absorb ability the same beta update build they gave the reasoning why priests don’t get things is because other players have them… yet mages and hunters get what priests have.
That logic is staggering and clearly shows an indication of a double design standard priest class is held too.
Also our DPS cooldown has a cast time… on a class/spec that is very immobile and easily shut down in PvP with no way to make it instant cast. At least with Dark Archangel in Cata, it was instant cast once you charged it up with Mind Flay damage in Dark Evanglism.
So TL;DR
Priests needs a dedicated and devoted wow developer to spend the time and sit down and really figure out what shadow should be.
Many posts and threats have provided numerous feedback as to how to achieve this, myself included.
Because it’s clear at this point that blizzard needs as much help as they can get.
If anyone is curious as to what my feedback would be, I laid out all my ideas for both current talent trees and a possible direction for Hero Path talent trees going into TWW here…