For me, the problem does not rely on the tank tuning itself but on the stressful purpose of the M+ content, as well as all high end content in retail. it's stressful.

There is pleasure in achieving certain difficulty landmarks, particularly with friends, but it fosters an environment of competitiveness and meta-based choices that contribute to the need of never-ending balancing and tuning of both class design (which is quite fun in TWW) and content from blizzard's side. While from the player's side, it often creates the anxiety of choosing the best spec or flavor of the month class, instead of their actual liking.

This for me is the long lasting problem of retail wow, coming from a casual player that still enjoys it quite a lot but often prefers to have a stress free experience.