Why is the healer class basically a one spell dps class?

[Roeshel]

I remember playing Aion, a PVP game, and getting shrekt on the field by clerics. Healers can be fun to play, if they're allowed to play the game. Someone compared XIV's combat to an ATB system and with that outlook I think healer could be really fun if allowed to do more than press a button when anyone's HP dips below 70%. Have healing phases such as that part against High Seraph Ultima where the entire alliance's HP is plummeting but also DPS checks where little healing is required and it's all about slapping that HP bar.

AION is one of the few MMOs I have played before. The clerics had dps chain skills which were pretty fun for solo leveling. The game was ruined by p2w tho so I left soon after hitting max level. The low rng for upgrading your items was intentional so that you buy those stones from the cash shop.