Shouldn’t a character’s win rate always tend towards 50%? That’s the point of matchmaking. It will eventually put you at a place where you win ~50% of your games.
Mercy is in 150% of games. 50% of games she is going against another Mercy. The other 50% against a team without a Mercy.
50% of games are guaranteed to have a Mercy winning. 50% of the remaining 50% will have a Mercy winning to (her win rate is 50% according to that dev).
That means a Mercy is on ~75% of all winning teams. Oddly, Brigitte isn’t on nearly as many, having half the pick rate of Mercy in GM.
Nerf Mercy, or buff Ana, whatever. My only point is that Mercy is over represented AF in the current meta. But, so are Rein, Zarya, and the snipers. That’s the nature of Overwatch metas. A handful of heroes will have SUPER high pick rates.
It is however VERY annoying that Mercy has had a SUPER high pick rate for a LONG time now. One day maybe we’ll get a meta where there are multiple viable team comps that counter one another.