Uhm let’s see, first is what you could consider her class, she’s basically a Cleric, like a real white mage kind of deal, no holy magic that deals more dmg than regular black magic
They made her originally as a better than most healers in the game, which at the time was the number she got now, 50 hps, this number was the highest amount of healing a healer could dish out and her ult as you know was mass rez
Mass rez wasn’t all that bad but potentially could enable crazy powerful strategies that started creeping up slowly but surely, strategies that encouraged counter intuitive gameplay like commanding people into point suicide and whatnot
More importantly is the fact that original mass rez didn’t have invul frames and it took longer to charge than valk currently does, so the ult itself was heavily gated as it should be, the price to pay for such a powerful ult was Mercy’s viability and it was soon obvious that her place in the game was non existant, as such people claim she was balanced before when in reality all she was, was an incredibly shackled character by the sole existance of her ult
Buffs followed soon, they made her a better healer with 60 hps and added invul to rez, admitedly this version of Mercy was sort of balanced but considering she was just overwatch’s least dmg oriented character, all she was able to do was heal as much as she could and then focus all of her mental process into rezzing, rinse and repeat, her mobility was subpar and her contribution to the team was sort of low, she was sluggish and pretty dang boring if I may add
The idea behind Valk was to release Mercy from rez burden, freedom allowed developers to go ahead and increase her survivability by adding more mobility, valk increased her total healing output and gave her a cool flying moment, her utility as a scout shot through the roof with this as well but people tend to overlook the power of scouting abilities (sombra…)
but the truth is that Rez was still just too powerful, even after all of the nerfs to it, Rez has remained one of the best skills for almost a year, be it single target or AoE, Rez is just that powerful but there is only so much you can nerf a skill and the goal is never for a single skill to be balanced, the goal is always to balance a character’s value for a team and Mercy’s value has never been just rez
Valk single handedly increased her healing done by quite a bit as well as added mobility with bunny hop and math is very simple here, if you added something that increased her healing output, then nerf her healing output to what it was originally
Yes now we have characters who heal between 70 hps to 140 hps but they have to fight against reliability, something that Mercy has a ton of, lowering her healing is literally meant to lower her value because currently she just has too much
it has nothing to do with hating Mercy, it’s just the right thing to do