I would argue that i fights remain as they are with 100% uptime than they should pay a tax for it.
Casters all have tools for movement, but it’s not as easy as not having cast times. NIN, DRG, RPR all have utility. RPR in particular has both a party wide damage up as well as a party heal. DRG used to have dragon sight.
Groups are always going to prefer the Rez for progression. It feels bad that caster is the only role that is essentially divided in half. I think PCT and BLM should be able to compete with melee DPS for the 4th slot.