This is my personal opinion, formed by observing complex PTSD people on the discussions boards and reading about therapies and cures. The fast, quick cures happen with simple PTSD not with complex PTSD.
Childhood trauma holds so many more entanglements with our development as a child. Layer upon layer of coping mechanisms entwine dissociated parts of our being. This presents and prevents healing happening in an hour or a visit or a week or a month or not at all without enormous effort and work.
If you find yourself viewing this blog, you likely have complex PTSD or healing is more difficult for you. It took me 6 months of sitting 3 hours a day to even budge my trauma. It is curable or a symptom free state attained, however it does not happen easily or on its own. Time does not heal childhood trauma. Probably the opposite is true.
Therapies that work on complex PTSD are DBT and ACT or acceptance therapy. Both are mindfulness based and evolved because the old models of cognitive therapy took too long and were not effective.