Literally 75% win rate against Tracer and 75% lose rate when not against Tracer. That... kind of looks like a counter to me.
Dragging a charging Varian out of position with blinks is a cute outplay. But...
You need blinks available. One blink is not likely going to get you to safety; even two may not if you're trying to harass his backline instead of just poking the tanks. Needing to keep those available dramatically restricts your mobility.
You actually do react in time. It's not trivial; even in pro play we've frequently seen Varians managing to land taunts on Tracers. If you pull Taunt + Parry Varian into your team, he may die; if you get taunted around his team, you will die. The risk/reward is in his favor. And that move becomes harder if your connection has much in the way of latency.
He needs to make a significant charge to close the gap. If the real high-value targets are persistent about just staying on the wrong side of Varian from you, you can't exactly walk or blink past him to hit them. He's peeling you off his teammates simply by having Taunt, without actually using it.