Because that’s only one facet of the issue (though it is a big one)
Even in something like Alexandria yeah sure the lack of gear means we take more damage and actually have to be healed more but let’s say they fixed the ilvl sync and we were permanently how we are in Alexandria. It still doesn’t change the fact that the rest of healer design is grossly boring.
The reason why ten different people have 10 complaints is because every facet of healer design is broken
-damage is boring
-healing is too low (it’s tolerable in something like Alexandria but only in the boss fights)
-the healing kit is bloated and non interactive
-the healers aren’t balanced well internally
There is no “single thing to focus on” that would actually fix healers because they are broken in so many different ways