As OldUser said, it can actually save some time for some applicants (I know not everyone has a fast process). One of my parents applied 90 days before their 5th year anniversary. Well, they became a citizen on their 5th year anniversary, so in that case it helped as they were done much earlier than if they had sent the application past their 5th year anniversary.
Again, I know not everyone benefits from it (I applied early too, 5-year rule, and it took me 14 months to become a citizen 😆)