Saying "PvP proves Sprint is unfair" makes no sense, because the specific situations that require sprint in PvP do not exist in PvE.
You need sprint in PvP to either catch up or run away from a target that is also using sprint (which is possible ONLY because your opponents are real players too).
Opponents in PvE do not have sprint, therefore anything and everything can be reached/outrun/evaded without sprint.

If you are calling for an ability that makes it easier for you to evade AoEs as a melee, I'm going to call for equal HP pool and def on mage as melees have + the removal of the need to stand still during casting,
otherwise that would not be fair and balanced either, that melees can get hit more and can keep attacking WHILE evading AoEs while I have to cancel everything just to move.
Some things are just differences in role design, not actual imbalances. I vastly prefer these differences over everyone being exactly the same, just the weapon animations being different >.>