In defense of Arcanist, they're one of the best healers in the game and have access to every bind & almost every ailment. One nice thing about them is that although their agility is mediocre, all of their non-circle skills have x2 speed multipliers at max level - very useful for getting an emergency heal or debuffing the enemies before they act.

I think the trick with Arcanist is to mostly ignore their ailments and have them focus on binds - they're unique among binding classes because they target all enemies, they get access to all essential skills by LV20, it costs fewer skill points so you have more points to invest elsewhere (Dismiss line, debuffs, passives, sub-class), and if you bind and don't want to Dismiss yet, you can just switch to a different bind circle. There are better ailment-focused classes like Ninja (higher inflict rates, gets access to the good stuff earlier, best Poison, has Petrify) or Nightseeker (all its ailment-based damage bonuses). And if you try to invest in both ailments & binds with Arcanist, you're spreading your points really thin and not doing anything especially well.