Sometimes we do things just because we have committed to doing them.
There is nothing inherently good or bad about this process. But it does let people know that they can rely on us. That if we give our word, it will get done.
Perhaps more importantly, though, it allows us to trust ourselves. If we have a history of delivering on our commitments, then we know we can do it. We also know not to enter into commitments lightly.
It can be useful to look at our promises and see when we have delivered and when we have not. Do the people we have broken promises to treat us differently than those to whom we have kept our word?
What if we never broke a commitment? What would happen then?