A lot of US shows (1000 lb sisters, My 600lb Life, Family by the Ton) make it look like WLS is a magical cure. If you watch the Where Are They Now programs or Google the participants, you usually find a good number of them regain weight.
I firmly believe that therapy would do more for most people than WLS. I'm not saying there isn't a place for it and it definitely works for some but those who have had trauma in their lives will always turn to food, even if it means eating until they are ill.
And the successful ones are definitely not pouring ghee onto their bloody popcorn.