As title says that is what should be a step(not the only one) the game should take if it wants to maintain the holy trinity of tank/healer/dps.
PCT does not need an AoE heal, that should be for PCT only same for their shield, it should be for themselves only.
Mnk does not need an AoE heal, self heals fine, not party wide
Smn does not need AoE regen it should be for Smn only
DNC does not need AoE heal, should be for themselves and Dance partner only.
War should not have an AoE shield+Regen, make it a AoE shield at least or AoE shield with self regen at most.
These changes would keep each job’s self sustain intact for themselves, but take away their ability to be able to keep a party alive longer, it’s not their job to maintain and manage the party’s hp it’s the healer role that should do, they should only have to manage their own hp at most for dps, using mitigation on top for tanks.
Healer role should be the only role to have AoE healing in it, should not have any AoE healing within the tank or dps roles.