I played WoW for years with those "weak ass heals", and their "stronger but healers still heal nearly full time" earlier incarnations, including in progression content. I know how it plays. Healers actually healed. Fights could kill you with one shots, with people eating avoidable but not lethal damage until you went OOM trying to keep up, and such.
The idea that this is some revolutionary insane concept is silly when the biggest MMO to ever exist does that exact thing to a higher degree than what's being proposed. You know what wasn't a thing in WoW? Healers spending 80% of their time DPSing and not healing.
I tend to think healers should spend more time healing than DPSing, and want a healing design to support that. Crazy stuff, right there.