Sorry for the unclear wording. I feel like (can’t exactly break out the WoW devs’ design logs, but if you look at average mitigation over time and the like, this is the conclusion I arrive near) the tanks were balanced without the kiting expected, with mobility (relative or true) instead being a feature meant for responsiveness in grabbing attention, interrupting, repositioning the mobs themselves, etc.
So, barring already well-discussed undertuning here and there which amounts to surprisingly little overall, they’ve all about the same defensive power when standing their ground.
But now, what happens when we add kiting? Suddenly true mobility turns into a whole lot larger defensive advantage. And it’s not part of that defensive equation. The difference between the relative mobility of an Avenger’s Shield and the true mobility of an Infernal Strike or Heroic Leap becomes huge in terms of defensive benefit. Yes, AS via First Avenger has tremendous defensive benefit, too, but it’s accounted for, while the gap in the ability to gtfo doesn’t seem to be.
No, but come to think of it, there are very few, if any—not to say that I’d want those either, as it’d just force the opposite end of the mobility spectrum if they were prominent.
If you, say, had a bunch of powerful slimes that’d leave long lingering sludge as they move, that’d be something, but… I’d honestly rather avoid that kind of thing except as a novelty of a particular trash pack or boss add. And I certainly wouldn’t want to tie throughput perks into standing still. BfA’s ‘standing still’ bonuses were trivial and yet still annoyed me.
To review, I just want to reduce the defensive benefit of mobility so that competing forms of defense don’t feel as watered down or deemphasized by comparison. I still want mobile tanks (I’d even prefer that Prot PLD, for instance, have a bit more mobility); I just want it to be a less sustainable mode of defense.