If you know what you are doing once you get to level 48, ele shaman becomes a leveling machine through the art of aoe grinding.
With Earthbind totem
Thunderstorm at 24
Mastery 15% for CL to overload at lvl 29
Earth ele at lvl 36
Lava surge at 40
Capacitor totem at 44
Earthquake at lvl 48
Warmode just makes it ridiculously easy.
ER/CoT/ES/SEorLMT/NG/PE/SK
Warmode talents take EA/CST/Skyfury
This will give you 180 maelstrom
Start by pulling 3-5 mobs and kill them with CL saving your maelstrom
Repeat this until full maelstrom
Then grab 5-10 mobs drop cap totem and all your EQs. Spam CL/Heals as needed. Loot and move on.
Once you get the hang of it you can pull crazy numbers of mobs. And as you level and get better gear and more talents/spells you become even more efficient.
Oncce you get azerite gear just focus on defensive traits. any healing shieldding traits. Pack spirit and vampiric seed are amazing stacked. Either get healed while you nuke them down or drop all your ES and stand in GW getting healed to full.
You can SK+CL/EQ mobs every one min
You can (with SE+PE) SE/SK+CL/EQ/SE AOE tons of mobs down every 2.5 min.
You can EE+PE/SK+CL/EQ literally an insane amount of mobs every 5 min (remember to heal your ele)
If you do it correctly there is literally zero downtime aoe grinding as ele. I am on my third shaman leveling as ele (damn heritage armor).
On topic ele is amazing at grinding old content.