Without being dramatic, I just feel that for the dev (or just Y.P?), the healing progression is just "figuring out how to optimally heal the fight" and it stops here.
As in, a DPS needs to optimise its rotation to the constraint of the encounter (most iconic example would be BLM) to dish out optimal damage.
For healers, our DPS is directly correlated to our ability to optimise healing. The more optimised your group is, the more glare you'll be able to dish out until you effectvely have 99.8% uptime with the bare minimum amount of gcd heal.
Which is sound I mean... this is exactly what happens. Until we reach that point, having extra DPS button could be seen as irrelevant as we're already busy figuring out how to optimise the fight.
The issue is that once that point is reached, DPS have a busier rotation which keeps the game more engaging. However, when we do, we're left with a rather boring format of 1111111111.
And on top of that, as other players help with mitigation and we get more gear, we end up doing less and less.
It's kind of sad that the most engaging Extreme fight are the one where everyone is kind of bad, as in, tank don't do any mitigation, DPS collect vulnerability debuff like pokémon cards and your other buddy healer only healing knowledge seem to be, spamming Medica1 and Cure1. (And dying a lot)
Basically, healers have a diminushing return on fun.
The better we get, the more gear we have, the boringer it gets.
