you obviously do not play this game.
Balance is one of the worst PvP specs in the game, all it has is starsurge, it has no utility, its heals are nerfed, and if you don't have the right azerite talents, you are dead.
" Feral still has flight form " Flight form can't be used in combat, and if you have to root and fly away you've essentially are saying i can't win,and if they break the root, good luck running, Mobility is a void point since everyone has mobility, heal you get free sprint potions from bg's, plenty of 150% move speed potions in the A.H azerite talents that give movement speed don't know who you're pvp'ing because it sound like you're fighting casuals or 2 v 2 arena jockeys who have a healer on them at all times.
Oh and if you think Feral Druid has more Mobility than a Demon Hunter you seem to forget that D.H move at a faster speed from mastery 100% of the time, can charge twice, leap with metal, have a talented charge ability , snare talent and the ability to heal off all damage they do with leech. All they have to do is kill a critter and they get like 40% or more of their health back.
soul scape playing D.H
https://www.youtube.com/watch?v=MVv-RjgTaKM