And now, I'm back to my White Mage. Healing since Shadowbringer is just so difficult!
Not being funny but this is a total inverse of my experience.

As one of the most DPS-aggressive WHM's who makes a conscious effort to heal only when necessary, including casual double/triple pack pulls, I have yet to even be challenged by Shadowbringers. 75% of my time in dungeons is spent casting Holy. This was the same when levelling as it is for me in Expert at 80, and even the new trials (where 80% of my time farming EXTania was spent casting Glare on repeat). Whether it was levelling content, dungeon content (which I spammed incessantly thanks to instant-queues), or EX, the result was the same. Heal occasionally but have the freedom to be a DPS monster.

Don't believe me? I stream pretty regularly. Failing that, I could make some simple videos of me healing dungeons. Unless a tank is wearing tissue paper and/or being a mitigation scrooge, all you're going to see is holy explosions 24/7 with the odd Heal thrown in. Worse case scenario is DPS being asleep and mass-pulls going on forever, to a point where a tank eventually gets low enough to render you into cure-spam territory, which is quite easily remedied by oGCD's if you have them, but can (eventually) become a problem with enough damage and no backup buttons.

On the flipside, I'm sick to death of getting AFK Healers and Over Healers whenever I stop playing WHM and swap to my tanks. My last dungeon involves H.Switch with a White Mage who spammed Medica II over, and over, and over, and over, often even before pulls and constantly throughout them, to the point where I got to enjoy the sight of my first WHM with actual MP problems for many expansions. Joke is, we still wiped on a trash pull despite this sort of drivel, with a tank in full 390 (with materia) and constantly cycling mitigation buttons.