We don't have "mere supports" anymore, in addition, that's not unique to this game. In at least one other game that I played that was designed for PvP , the highest ranked players , out of all jobs, were what you (rather dismissively) refer to as "mere supports". Given 2 skilled players- it definitely was more challenging as a DPS to compete against someone who had both good attacks , utility and heals.

All of this to say that we don't have roles any more, I can understand the argument being made that some jobs should have more utility or more DPS skills than others, however all jobs are "resilient DPS", and yes- given a skilled player, why shouldn't a healer or potentially a tank (a) be able to significant damage and (b) potentially be a difficult opponent? It's not unknown in PvP games.