For me personally damage kits do not need to be reworked at all. They are there to fill gaps in a fight which there should only be a few to "catch your breath".
But if role parity in the playerbase is what SE cared the most about I wouldn't even mind them introducing another healer job with Dawntrail and diversify playstyle among the jobs.
The thing that needs changing most is encounter design. The more tools you have in your bag the more and faster encounter mechanics would need to be in order for them to be useful.
This never happened however.
I suspect it is because of SE's push for "brainteaser" mechanics that take a lot of thinking to figure out and a lot of training to react in time to. All the while you do still have to press buttons, as healer especially. You don't want people to die, they need to learn mechanics and you as well. The solution to not overwhelm you is to make healing a 1-button endaevour.
This design naturally sucks most individuality of roles out of the game. With less individuality there is also less responsibility for each other and less power imbalance. I am not even sure which of them is cause or effect.
But I would really like to think the community is mature enough for this to not be a factor.
I do love the more tactical gameplay as it was peak in ARR.
If you take a look back, encounter design was the most diverse there ever was.
Here are a couple of examples of what exists:
- On Ifrit Ex you have got to deal with instant TBs that reduce Max Hp and continous raid wides. While also having to monitor youself for a debuff and leave party healing to the other healer when you have it.
- On Ramuh Ex it is instant TBs that get more frequent the further in the fight you are. The fight also features a kind of resource mechanic where your group balances mechanic safety versus increased incoming damage. Further it has a certain mechanic where using actions causes damage to yourself so you have to keep an eye out and cover for your coheal in case they get it.
- On Leviathan Ex any healing action executed on the tail tank gives a stacking debuff that reduces healing range. Dealing with this has the healers swap taking care of the tank while positioning in a way they will not accidently hit the tank with aoe heals.
- On T9 you have got Multihit TBs, raidwide damage while everyone being spread across the whole arena and the infamous last phase that is just unpredictable.
- On T13 there is more Multihit TBs and later Multihit Stack TBs that both healers need to heal into. It has spot healing on DPS players, followed by TBs and lots of raidwide damage.