LMAO, Rez isn’t that strong.
First of all, Rez not only has a longer cooldown than all other abilities, it has a channeling time of nearly two seconds where she can’t move and plenty can happen to her during that time if the enemy team remembers to put her in check.
Secondly, for it to be useful, at least one of her teammates has to be dead first and then within 5 meters of her. That’s one teammate who won’t be around to protect her. So if the teammate being rezzed is a tank, that’s one barrier out of play. A dps? One less source of damage. A secondary healer? One less healer.
If in the middle of the fight Mercy’s whole team has to temporarily disengage, throw themselves around Mercy and the target she’s rezzing, and worst of all play without receiving healing from Mercy as her rez is being channeled. The enemy team can then take advantage of the moment to either reload clips, heal up, reposition, or flat out counter the Rez with a little aggression.
Next, the way Rez works can be exploited by enemies looking to counter it. Simply stand over the area where the soul of an opponent you eliminated rests and the enemy Mercy won’t be able to fly to rez it safely.
And finally, even if Mercy pulls off the Rez, you can just kill that opponent again. No. big. deal.
Mercy has been nerfed enough as it is anyways, and nerfing a popular support hero ain’t gonna suddenly make Ana a more desirable pick; you just add to the number of support heroes no one wants to play. If you really want Mercy to be more skill-based, then she should be reworked out of her passive playstyle.