I see people wanting 80%+ healing in content and I have to ask... do you want it in all content? Because if your healing the same amount in a 4 party dungeon as Ultimate then I can already see issues. The need for high healing percentage also increases the personal responsibility which tends to push people away from a role, just look at tanks.

I would also like to note that having more healing doesn't mean you will be making healing engaging content. Swapping Glare with Cure ends up doing the same thing.