Canceling the booking itself doesn’t trigger a refund automatically, this depends on the website and/or host terms, so it’s always there just to give the ability to let the host know that the customer will not show up, this also frees the booking dates in the calendar (allowing for another booking to be made). If you want to hide this link anyway please try this CSS snippet:
.hp-booking .hp-listing__action--cancel {display:none!important}