Ever since Stormblood dungeons have been face roll anyway. Heavensward didn't have this focus as most of the trash pulls seemed to hit WAY harder, and the heavensward dungeons were designed VERY WELL in spacing out each pull. There were times when you could pull everything, but it was much fewer and far between compared to Stormblood or Shadowbringers. Healers had to focus a little bit more on keeping others alive back in those days, this seems to be more exclusive to heavensward. It seems the healer community got up in arms when they were forced to DPS in AS1-12 to meet those crazy enrage DPS windows as those were REALLY hard savages, and this may be where healing hasn't been much of a focus in low end content. I have seen a huge shift from pulling WALL to WALL in stormblood and shadowbringers, and tanks have benefited from this.
I think the balance we have now with healers DPSing in dungeons, and tanks picking up some of the healing is dang near perfect. Tanks self sustain is strong due to the community liking more and more pulling wall to wall. It's faster, and healers DPSing make it even faster. Tanks in savage are just vastly under appreciated for their mitigation and self sustain. I appreciate that tank with 200k HP when they take a 120k tank buster to the face. Pop the blackest night....pfft. Thrill of battle + Equilibrium...poof 80k HP or Inner Chaos + Nascent x2. Clemency....60k HP each cast or combine with requiescat. etc. etc.
These gameplay practices for tanks is second nature. I have soloed MANY bosses from all old content. Which makes me believe that Tanks will NOT get much of a DPS buff in Endwalkers to balance this out, and most of the DPS will go to the DPS classes to leverage the "holy trinity" playstyle where ever class is needed to survive. Tanks can soak up damage and can hold their own. DPS bring the REAL pain and can take some damage. Heals do the least amount of damage and get smoked when in danger. With the way agro works now, tanks don't need to do as much DPS as a monk. I would rather see that damage buff go to the DPS classes personally to balance out the enrage timers.