Yang Yi is not the most successful spy, nor the most formidable one, but he is definitely one of the most successful multifaceted spies because he possesses resources that all spies envy.
Think about it, Yang Yi doesn't really have any remarkable achievements to show for, or put another way, his performance doesn't match up to his current identity and status. However, he is able to move with ease among the several largest intelligence agencies in the world.
Is this luck? No, Yang Yi is able to do this simply because he is valuable to use. Everyone wants to get some benefits from him when dealing with Yang Yi, and in order to get those benefits, they are willing to first offer some to Yang Yi.
As you can see, in this world, having the value to be used by others is so important. Even if Yang Yi becomes someone utterly useless, he can still be the favorite in the eyes of various intelligence agencies. Why? Because he already possesses enough resources to exchange with others.
