@AnT see the thing is, you don't need a healer if you are able to take down a boss in less than 2 minutes with minor injuries. Those minor injuries can be handled with porions and whatnot. You need a healer for a prolongued fight, you need a debuffer to nuke your target. Sometimes, if an enemy is string enough, he can one-shot you despite all the buffs you have on you. If the healer is unable to ressurect you, then you are done for. One strike and the boss kills the so called "hero". That is why a debuffer is important. If the debuffer can reduce the resistances, defences, and stat effects of the enemy enough for difference in stats to not matter, a beginner part can easily take down an endgame boss. See, having 100 agility will make the boss strong, but imagine the debuffer in your party casts a curse that increases the weight twofold for every point of agility the boss has. Suddeny the boss' body wieghs 100% times more despite having all that agi. The boss who is sued to moving in his normal weight is unable to handle the extra weight and becomes sluggish, but the thing is, it us usually tenfold or twentyfold increase not a twofold increase. A good debuffer will cast curses upon curses, status effects upon status effects, so that the enemy has no choice bu to accept its death at the hands of a a swordsman or other weapon weilder who is far inferior to itself.
Don't put me together with those shallow swamp dwellers who enjoy fan service and cheesy harem. I am someone who looks beyond simple harem and comedy and enjoys a good story.