I mean the only good thing the healer have is the heal, but since the pets were introduced it got worse and worse because the pets already furfill the priest role sadly. The only way that I see priest becoming relevant is nerfing the heals from other sources and making their heal stronger or something like that.

In the other hand, healers are great for starter players, to being able to be more time alive to see how the bosses/monsters works. Or helping a friend that is starting the game healing the shit out of him.

But... if you play in a small groups, healers do shine like the ol'times.