There’s a difference between when PvE gear gives you a small boost in performance for 1 season vs when it is absolutely mandatory for everything. Noone is saying we should be able to buy mythic item level gear from a vendor. Plenty of us have lobbied for the return of the WoD scaling system for PvP gear.
And also there are plenty of high rated players that have complained about the current gearing system. Here is one of them: