Enhancement Shaman downsides:
-Bad mobility (leading to bad uptime with how much mobility overall has been added to the game over time).
-Bad CC. Hexing in melee is unreliable, Lightning lasso is decent but you cannot do anything during the channel aside from move, and Cap Totem is our only reliable form of CC which we spend 2 talents on to make worthwhile.
-Bad off healing with the removal of AG. Stormweaver is hardly taken as it competes with too many good talents (especially other defensive talents) and Earth shield also gets purged/falls off constantly, requires too many globals to reapply and losing that 20% healing bonus feels bad.
-Bad survivability with the loss of AG as a personal. Our defensives have long CDs and we only have a few of them. Astral shift (with talent) is 1 1/2 minutes, Stone Bulwark is 3 minutes, Earth ele is 5 minutes, Natures guardian for Enhance is 45 seconds. Burrow feels necessary to take which feels bad as it removes the option for damage/utility talents, whereas other melee barely have any major defensives in their honor talents.
-Great damage that is very counterable. Doom Winds duration is 8 seconds, Disarm lines up with it every time which takes away 5 seconds, and any CC after usually takes up the remaining duration. On top of that, it is very easy to kite an Enhancement shaman as well.
-No Mortal Strike effect.
-Purges easily take off Earth Shield and Skyfury reliably with no punishment, hard to find globals to constantly re apply either of them as a melee with high APM.
It would be great if we could solve at least one of these issues. Enh shaman does have great utility in PvP via Grounding, Tremor and Earthgrab, however Shamans utility over time has been nerfed repeatedly or given to other classes in certain ways. For example: Poison cleansing totem was nerfed to a much longer CD, Wind Rush is a long CD, Static Totem got nerfed to a longer CD and competes with defensive honor talents for Enh, and Tremor was basically given to Warriors in the form of Berserker Shout but can be used while in fears/incaps/saps whereas Tremor cannot be, however it has a shorter range. Our off healing with the removal of AG is also quite bad now.
Maybe we can look to improve Enhance mobility? Feral Lunge could go down to a 15s CD and Spirit walk could grant immunity to slows/roots for its duration? Spirit walk being a 1 min CD that you can immediately get re-rooted or re-slowed on as soon as its pressed feels terrible. There are a ton of passive roots/slows in the game now, hero trees added a few and some spec/class trees have a lot.
Just improving one of these downsides is all thats needed. It is okay to have downsides in exchange for utility, but again that utility has been nerfed a lot overtime and in some cases given to other classes. Grounding is the one thing we really have left that is unique and very good, but it is not enough to compensate for the multiple downsides this spec has.