I see you did not at all mention that tanks are just fat DPS and your only change to them was removing party wide mitigation. So you're fine with the majority of a tank's kit being dedicated to DPS? Because you realise that it's stupid to have a tank with ~3-ish attacks and everything else being dedicated to aggro or mitigation, right? So why are healers so special that green DPS is considered problematic and conflates identity between roles when blue DPS isn't given the same treatment?
They're never going to change fight design to suddenly require healers to dedicated most of their time to healing. That's never been the way the game has worked at any point. DPS has always been everyone's responsibility. Suddenly amping up healing requirements would not change this.