Actually…
This is so false. How to fight around it? Take advantage of the situation. The ressed teammates, unless your team is already at a severe disadvantage, will have the advantage. Take advantage of that. How to work through it? I’ll just give one solution:
Use an ultimate.
Nope. Counterplay isn’t just cancelling things before it gets pulled of. It’s anything that negates the impact or value of something. With that in mind, anything that negates or devalues mass res efficiently is an counter.
You know what’s garbage? The fact that you didn’t kill the Mercy and proceeded to kill her team excluding. Also,
This is just something you pulled out of thin air. This is not a thing at all…
Because most of the scenarios of, “boo hoo, mass res is bad” give scenarios where they kill entire teams except the Mercy. Yeah no, that’s a skill issue.
If you think ressing guarantees an instant win, I can already tell you don’t know much about the topic at hand. In which case, I’ll redirect you to this thread:
Nice strawman. I’m not arguing this at all. Also, I know it doesn’t take skill to do such a thing. That being said, stuff like this punishes itself. Like I’ve said which you’ve seemingly ignored, hiding counters itself.
This is just as bad as hiding and is not a good strategy which is what you’re portraying it as.
Unless you consider stuff like expending one ultimate or staggering death as extremely skilful then no.
Again, this is a skill issue which you’ve denied in the first part of your reply…
What’s this supposed to mean? 
Other supports were chosen before her rework as well. 
In fact, she was underpowered for a long time during her pre-reworked state. After a year of reworked Mercy, this is the first time we’re seeing “diversity” and even then, the support roster still has major issues with certain heroes still being left in the dust.