How can we defeat a team of 6 tracers?

As someone who is extremely effective with tracer, what I absolutely hate to see when I play is a junkrat. He's by far the best counter for her. Ive been one shoted by his grenade launcher so many times. The steel trap may be hard to make hit but once it does, it deals an immediate 70 damage and stays clinched longer than 3 seconds making her rewind completely useless. You'll probably still die a good bit due to low hp but you'll be killing tracers left and right. Mcree isnt as good at countering as everyone says. At least not if the tracer is halfway decent. His flashbang doesn't last long enough and the reach is awul so it's easy to dodge.