It gives him time to miss you:
You also will ruin your chances of getting back together and making it last this time.
That is probably why it is the most popular version.
I have now realized how much my anxiety affected our relationship.
The only way to win is to not talk to him.
If after some serious introspection, you decided that getting her back is the right thing to a guy likes you, you need to know that nc alone is not going to bring you together.
More often than not, the best move is the one you least expect it to be.