The truth is often painful, it hurts, because it is so ugly. Many people do not want to accept that the world or themselves are currently as they are or are. They do not want to live in that world or recognize how they are living. Denial is easier to accomplish than the hard work of facing darkness.
Occasionally we do not lock ourselves up in a world of lies so as not to harm the person we love and we resort to lying so as not to hurt the feelings of others, but no, we realize that we are not doing the damage ourselves.
Lying hurts more than the truth. Once people learn of the lie, it's a betrayal that hurts far more than the truth would have.