The problem with faster everything is that it reduces reaction time more and more and we end up in those binary situations where if you're fast enough you're alright and will find it easy, and if you're not, you're dead, your tank is dead, or you wipe the party depending on the content, and you'll just feel frustrated. Healing is no different, if one can heal anybody to full under a GCD, and then the mechanics can drop someone so fast in counter reaction to even prove remotely threatening, especially since MP management is a shadow of its former self, then you end up exactly in that kind of situations, and it starts even in casual. It's also similar with uptime and casting, and now you exactly have this displayed into full reality by BLM main vets that tell us that BLM was already very mobile and had all the tools to deal with uptime (which I don't doubt) confronted by everybody else telling them that it was unsustainable. More and more DDR mechanics where it's all about standing in the right spot or die/wipe, etc.

The whole game's essence has become very binary and it drives wedges into the community, while pushing into unsustainable design where the smallest deviation can snowball into a myriad of issues (as seen in the DPS class balance around a singular damage metric).