What is the benefit of a default upload policy?

When you have no match policy, your default upload policy is applied as the match policy.
YouTube applies the default upload policy to videos that users upload to their channels, which produces better Content ID matches.
YouTube applies the default upload policy to videos that you upload to your channels, which speeds up the setup process.
If you don’t select a default policy, YouTube uses the predefined policy Block Everywhere.

The correct answer is:

YouTube applies the default upload policy to videos that you upload to your channels, which speeds up the setup process.