It’s fairly obvious to anyone who’s played against a decent mercy that her movement is way too much as it now. I know the guy in the clip is playing Sojourn so he’s having a harder time hitting her but in all honestly no character is hitting her when she moving like this.
Spoken like a true mercy player who plays her because they lack the ability to aim and are unwilling to put in the effort to develop it.
Her pistol is one of the more powerful support weapons in the game as far as damage potential goes like near Zenyatta levels, but when you don’t have the skill to use it and refuse to develop that skill of course you’re going to say she has zero self-defense ability
Vanishing out gives you survival. It doesn’t matter how much you focus fire where Sombra was, after the teleport is gone off, you don’t get to kill her.