I just thought of an interesting way to fix our right gear scaling and the currently useless Tenacity stats without SE doing a bit revamp existing gear.
What if Tenacity (which is abundant on all our gear) have different effect in tank stance and outside tank stance?
Tenacity in Tank stance would provide passive mitigation (something like 150 tenacity = 1% mitigation) but outside of tank stance it would be damage buff increase (again, something like 150 tenacity = 1% dmg increase or some attack power). Obviously, actual threshold would have to be balanced since in current 320 gear you can get ~1500 tenacity if you max the stat).

With such design, Tenacity would be highly desirable and pretty unique for tanks. SE wouldn't even have to go back and retroactively change all tank right side. It would provide some scaling from our accessories and make Vit gear fell more of an upgrade.