It advances the application process by fulfilling an important requirement on the applicant. It could also help the examiner in formulating a good first office action. If the first office action is not on target the whole process is delayed and you may spend money later on an RCE.
Why does the law require it? Patent examination is considered a one party preceding. As such you need to tell all. In a normal U.S. court, there are two sides adversarially hammering out the truth (in theory). That is why in an adversarial proceeding one side may not need to tell all. You can tell your attorney you committed murder and they can't tell the judge. If you tell your patent attorney (or agent) that you got most of the ideas from someone else, they do need to tell the USPTO. That is because the other party is the public and they are absent. You are asking the government to let you prohibit the public from doing something and the public isn't in the process fighting you. Since it is one-sided, you need to disclose.
You are required to give the examiner any ammunition you know of that could help shoot your application down. That is what you are compelled to list. There is no requirement to do any searching; there a requirement to let the USPTO know about references and actions that tend to hurt your application that you are aware of. Until a court decision a few years, patents were routinely being torn up for the "inequitable conduct" of not listing something that was potentially relevant. That situation is not as bad anymore but the common wisdom is that it is much better to list something that might be marginally relevant than to leave it off. When in doubt, disclose.
Examiners are organized: the topics they examine day in and day out and will likely reveal prior-art closer to the subject matter than the you have found.