To be fair, FFXIV PvP is… really bad, regardless. Very few people play it and while that system may work for it, WoW has considerably more moving parts to work with.
I’m pretty sure there’s, what, 10 jobs in FFXIV and they all perform a singular role? I think WoW has somewhere around 36 different specs and most of them play pretty independent of one another even if they share some abilities.
Not knocking FFXIV, I think it’s a great game (PvP notwithstanding), just that WoW PvP is intrinsically more difficult to stuff into a similar design philosophy purely because of the sheer spec variation it would take to pull it off. Imagine Blizzard, today, redesigning every spec to function a different way in PvP… that’d be pretty insane lol.