The “lowskill” consistent healing in the game is Lucio’s aura, if anything, which keeps not only Lucio’s teammates alive, but also Lucio himself through constant regen that unlike Mercy is not interrupted by combat. Lucio doesn’t even have to pick targets. All he has to do to be an effective healer is set his aura to healing and hang around in the general area of his teammates.
People keep trying to apply damage-dealer ideas of skill to healers, but it doesn’t work that way. It would only work that way if it were possible to out-heal incoming damage in Overwatch indefinitely. If healing were that strong, then yes, having a significant chance to miss would make sense and then the game would be about who screws up first between healers and damage dealers. But healing isn’t that strong.
Healing in Overwatch is really low compared to damage output, and it’s low by design so that fights will always resolve. It’s simply not possible to keep a team alive in Overwatch indefinitely against sustained incoming fire. In order to guarantee that fights will always resolve in a timely manner, healing must remain low (and for the record, 60 hp/sec was still low). Because healing must remain low, however, healing must be easier than dealing damage. Because damage is more potent, a damage dealer is rewarded more for scoring a hit than a healer is… so, it should be harder for a damage-dealer to score a hit than it is for a healer… and it is! Even Ana, the only healer with any significant aim requirement, still has overly generous hitboxes for wounded allies.
I’ve elaborated on this idea extensively in a previous post here: "Supports are too easy!"
I hope that you can give it a read, and that it changes your mind about the “skill” required for healing on any hero.