Ok, so bear with me here. First and foremost, this is merely a suggestion.
PvP is inherently about skill, correct? So why are gear disparities allowed? Any player that comes late into a season will tell you how hard it is to gear up and become competitive. How is a win by difference in gear considered a win when it should be about one player being more skillful than another?
Sooo, suggestion. Why not normalize PvP? When you enter a BG or arena you click some item rack that gives you all your pvp gear. Obviously this gear is the best for pvp and disappears when the match is over. Have some kind of equip all feature to save time.
To answer the need to incentives to pvp that people might have you could easily bring in mounts, titles, tabbards, transmog gear (no stats, kinda like challenge mode gear), etc. So there is still an incentive and those that perform the best will get equivocal rewards.