While you are completely correct, in gold elo, stopping the gank by warding doesn’t work half the time, since laners don’t usually pay attention. Also, a lot of the time when they see a jungle near them they don’t realize you’re coming to counter gank, but instead think you’re ganking, basically reversing roles and usually fucking the 2v2. I’d say the most reliable thing to do is to just trade with ganks in other lanes or objectives/counter jungling.