WHM has Assize and misery that they can passively charge,
Sage has Phlegma (two charges of 255 potency every 45 seconds), and the occasional Pneuma.
Astrologian's Star got buffed so now it's pretty good for damage (It's stronger than Dragonfire Dive, to put it into perspective), the occasional Lord, and they can use Divination to enhance everyone else's dps.

But SCH has....Chain, which works on single targets only, and Arts of War, which is the GCD hit any class has.

I feel like that's a bit of a weird design choice. It can't even buff people to do more damage, you will only do one button to dps and can't really hold a different CD for certain circumstances where aoe damage is viable (add phase in P3S).
It feels especially weird because SMN has had, since the previous expansion, an AOE equivalent of Energy Drain (Energy Siphon) which I might add, they don't even really need as their aoe damage is pretty good and consistently available.

I feel Scholar could really benefit from having an extra aoe they can splash into their rotation in Dungeons and any relative circumstance. Bane and Shadowflare were decent SCH staples before Shadowbringers, and I'm not quite sure if it would be a good idea to make a skill rely on Aetherflow charges because SCH tends to rely on them for healing in AOE situations.

And before you say Arts of War compensates for having the highest aoe damage in the game among healers, yes I know that, I'm perfectly aware that in a long term SCH could probably do more damage, but that's besides the point. It just has nothing going for it at all in the AOE department which usually feels very underwhelming when running dungeons.