I think "requires more skill to play but has a higher payoff" is a paradigm this game is desperately lacking. You could tell the developers TRIED this setup with 3.0 Astrologian, but also note that this was before many of the QoL buffs that cards have received since then too. In 3.0, Spire/Ewer were hot garbage, Balance was always good but Spread had a stupidly long cooldown and Shuffle could let you draw chain Spears back-to-back if you were unlucky. I think with the card system we have now, a meta shift to AST's old healing potencies might not be so outrageous - if you want that sweet deeps, you'd better be prepared to execute mechanics perfectly and have your SCH actually help heal a little to get it. Obviously, healing potencies would have to see a change across the board for this to be a likely outcome, but even a SCH's personal DPS can't match up to the combined might of AOE Balance. If Balance isn't going to be addressed specifically, then it should at least be significantly riskier to bring an Astrologian for raid content.

Something like that. I've long thought that Paladin and White Mage SHOULD be the powerful, easier jobs that help groups who aren't playing at the upper echelons of skill. That content should be designed around a PLD, WHM, and MNK's unique party defensive and recovery utility making fights significantly EASIER, but not required. The ideal end result? Firsters and speed-clearers will still push the ideal DPS comps, but more casual or mistake-prone groups can use those classes with superior defenses and recovery to help bounce back from errors made during progression.