Actually they do, but not in the sense that your system is failing behind in this case it would be your connection so the effect is pretty much similar they aren't the same thing, think like when you are downloading a file and playing an offline game the game wont be hit by the slow connection and you will be playing normally but if you are indeed playing an online game it will be affected since it relies on a connection o do things, if you are 100% sure you pc can handle a game with good fps make sure you have the better connection you can find in your area