I think time is part of the process of healing wounds but it's unhealthy to assume that it would work on its own. An open cut can heal over time but if it is infected and never cleaned, time can lead to loss of a limb or death. Similarly, if you receive an emotional wound and it's never addressed, all time does is let it fester and get worse. With proper attention, it really can improve over time, but time by itself isn't a magic wand.