Oof, tough question. I mean, I've been a main DPS since 2013, so playing a Dragoon comes off as natural by now. Or at least I hope so. Healing in dungeons or old raids does seem pretty easy since tanks nowadays are full-plated juggernauts bulldozing over enemies and healing themselves endlessly without requesting aid. On the Savage and Extreme endgame, however, it's pretty tricky. Besides being aware of the bosses' AOE, you must resurrect the unaware player who was caught and died in the middle of the battle and deal damage on the boss's downtime. I still think it's easier than tanking, though.