To OP’s original question: overhaul jobs entirely and abandon the trinity, Guildwars style. Give all jobs abilities to self heal or dodge mechanics, but in different ways.


-or-

Rework to make the trinity actually matter. I remember a time where (as a tank) I had to focus hard on my enmity rotation just to keep the boss’ attention if an ally were geared above me. Or, if I was geared well, I could sneak a few dps rotations before needing to build, enmity back up. It was fun having to actually watch and balance the enmity bars. Healers could actually overheat and steal enmity.

…ahhh the good ‘ol days.