And this is exactly why increasing the amount of healing required also doesn't work. You have 90 levels worth of content that healing is easy enough that you can get by with the bare minimum in most cases and still compete it. Hell, there's a short clip of a P4S run where the WHM was literally Medica 2 Spamming during the last 8% of the fight.
THIS IS NOT A JOKE.
There is no excuse to be casting Medica 2 back to back like this man was but here he was, in the final fight of the last raid tier, doing exactly that. This is how low the bar of entry is for savage that this type of player could get that close to clearing the raid tier by using Medica 2 spam.
This tier may as well have been Goridas levels of difficulty for this type of player that it really isn't a wonder at all why Healer participation wasn't particularly high this time around. I have no doubt this type of player struggled and probably quit the savage tier entirely, along with any other healer that fell back on their Medica 2 spam as their primary crutch because there was probably no way for them to handle it. Now imagine this type of player being asked to do even the slightest bit more healing in average content and I just don't see it ending well at all.