Has anyone quit healing?

[Rilifane]

Again for probably the hundredth time at this point, no, they have not. Certainly not "since partway through HW", a time where they outright said they were NOT using such a paradigm.

Even as late as 6.0, they weren't balancing that way - if they were, Misery would have been DPS neutral, and they wouldn't have reduced the DPS kits in ShB and outright removed Energy Drain. Only from "community" backlash did they reinstate Energy Drain in ShB (and half the complaints weren't ED being removed, they were that there was nothing to spend AF on if everyone was at full health - if they had given a AF spender shield like Divine Benediction or Celestial Intersection - that would have allayed a good chunk of those complaints), and didn't make Misery DPS neutral until 6.1. They literally are not, as Developers, paying attention to that or focusing on Healer DPS. It's ridiculously clear that they are not at this point.

Most encounters do not actually demand Healer damage for beating enrages. The only case this is true are early ilevel Savage clears and "Go play Ultimate" Ultimates. With a team of 99 DPSers, your Healers could probably only cast heals and your team clear the encounters with a healthy margin to spare. The Devs outright said in HW they did not balance around Healer DPS contribution, which means you can't claim they did so since 3.0 unless you're going to argue they were outright lying.

They said that, indeed. And people love repeating their statement again and again no matter how much reality tells a different story. This statement is outdated and outright false.

We had Alexander Gordias that absolutely demanded healer dps from both healers or it was literally not possible to clear, not even past min ilvl/ entry level gear.
We also had e8s which, again, was impossible to clear even with several 99 parsing DPS players and a good comp without both healers dpsing as well if you didn't want to wait until you half-outgeared it. There was definitely no "healthy margin to spare". Then also got p8s part 2 which still needed healer dps even after the HP adjustment.
And nor should all 4 DPS players expected to perform that insanely well and make no mistake while sticking to stronger comps for an entire fight just so the healers can sit with their thumbs up their butts the majority of the time.

So yes, healer dps has been expected in endgame content for a long time now and this is not just true for 1st/ 2nd week clears.
Blindly taking their word for gospel will not suddenly erase Gordias, e8s and p8s part 2 from existence where healer dps is mandatory to even clear past min ilvl/ entry level clears very early into the tier. And I can assure you that you also need healer dps in Ultimates, even if your DPS players perform incredibly well despite Ultimates generally focussing more on survival, mitigation and executing mechanics well.
Yoshi said a lot of things that proved to be false like his infamous "WHM does all the healing while SCH brings the dps" when SCH actually outhealed and outdpsed WHM - by a mile. He's not right all the time and he sure wasn't right about healer DPS not being necessary.