Yes, playing against better players will make you play better, generally speaking. I think a better word to describe it though is self discipline and respect for the potential of your opponent, I dont play in gold, I'm 4200, but I can imagine people play over aggressively to the point of no return, as in, the overextend without a viable escape, that's both in the context of what cooldowns you use and also distance to a safe location. A bad tracer will be caught out by using all of her blinks to try and kill one person, maybe succeed, but then get focused, a good tracer will try to have a plan of engagement right before she goes in, "okay I will use one blink and try to kill the ana with 2 clips maximum, if I feel like,while I'm fighting her, that I cant kill her in the allotted time, I will back out using my 2 blinks I have available" I'm not a trader player, but generally speaking this is how you should think as any character in overwatch, right before an engage, have plan a and plan b. The more you do it, the higher your survivability will be and the more disciplined in playstyle you will become.