The "meta" seems mainly to be for speedkill DPS league tables rather the progression/first clears.

For world first clears, the RDM was reported to be very helpful due to the res which one of the groups posted (actually better at ressing than the healer jobs thanks to dualcast) and this trickles down to normal player progression too (anecdotally my first o1s clear had both healers die at once but was salvaged by the RDM). Note that the first clears had VIT melded items for the DPS for those first clears.