I saw it more as a core mechanic than being the actual ‘rotation’ itself. But using the same scenario there could be things like buffs that only affect the ‘Astrologian-dancer-partner’ targets, mitigation/shields/regens associated with the ‘ast/dance-partner’ buffs to balance out spamming it on dps, increased or adjusted card effects based on who has the buff. Plus they could do things like having each consumed ‘star’ give a stacking buff to the Astrologian for ‘big potency attack’, and possibly a competing ‘big potency heal’ (not that we need any more lol).
It’s not much so that simple buff/debuff/utility skills themselves can make healers enjoyable, it’s the way in which they could be utilised to create a healer contribution that ends up more ‘support’ oriented than the ‘direct personal damage’ we have now. Essentially, moving healer dps (in various aspects depending on which job etc) from being less oriented on personal damage output and more on managing party damage output (rDPS?). This is assuming an ideal world where things aren’t ruled so strictly by the ‘120s burst cycle’ and so there’s more freedom in choosing when to leverage things like party buffs
It adds skill expression as it requires situational awareness that isn’t as necessary when output is focused purely on personal dps. And arguably you could even say it raises the skill floor, as having situational awareness is already something any healer is going to possess (albeit in varying amounts lol). But since it still calls on situational awareness over rotational / mechanical awareness, I’d argue it’s easier for healers to adjust to that style than one that’s more dps oriented, if not just because you’re looking at similar things (I.e party list, where they’re positioned, which attack is coming next etc). Plus, rewarding that situational awareness also gives people an incentive to indirectly improve their healing skills too, since ultimately good healing is about not just being able to react to set rotations but adjust healing as necessary depending on the situation (including minimising it)
And as aforementioned, none of that precludes any healer from also having interesting and fun dps options. Especially for Sage, which naturally falls into the ‘more dps oriented healer’ category for players who’d rather play a more ‘selfish-dps’ style healer. The current iteration doesn’t exactly fit what they set out to do but it could easily be adjusted through things like aoe Kardia, varied Kardia effects, more dps options between Phlegma/Toxicon/[Eukrasian] Dosis, and generally more of a ‘rewarded for aggressive play’ style