DPS stressors vs. Mitigation stressors

[Absurdity]

The problem with all of this is that you are making these proposals on your opinion of what tanking should be.
SE design the game, jobs and fights and have decided that tanking is something else. It's their game so it's their choice.
This game is based around doing the most damage you can, whilst barely surviving. It has been that way for over 5 years. Stacking mitigation is not fun.
Tanking is only "braindead" if you aspire to do the absolute bare minimum of what is required of you.

You speak as someone who has never done savage or ultimate content, or experienced actual difficulty in mechanics and combat. Tank mitigation checks exist. Punishing tank mechanics exist. Healer checks exist. And if you go into E3S at the intended item level, the tank buster will straight up kill you.

The ideas actually remind me a lot of oldschool WoW, probably the most boring tanking experience I've ever had.
It was simply "stack defensive stats and then stand there and get hit in the face". You simply got all the gear with Defense Rating (actually mandatory to a certain point to make you immune to getting crit, or your HP would simply be binary), Block Rating, Parry Rating, Stamina, etc and then you would stand there and spam two buttons that did 0 damage because you obviously had no offensive stats and most of your "active" mitigation had a cooldown somewhere between 10-60 minutes.

Add in entire groups who are elitist and looks down their nose at someone for not eating sleeping breathing this crap and you've got recipe for extremely unenjoyable gameplay.. then dev's like base the rest of the games classes and around the 2 to 3% of players that actually do this content most of the time.

Except that the boring job design wasn't the fault of "savage elitists" but of people who couldn't tell you their rotation if it slapped them in the face, didn't know anything besides Shield Oath existed and spammed their single target enmity combo like there was no tomorrow.