I wonder who is more eager to justify their decision and to tell themselves they're better off now: Those who tore down all bridges and left in anger? Or those who stayed and climbed up the social ladder even though they hate their live?
In some sense this is like asking who scores more goals in football by looking at whether they took a shot or passed it on. In the end I think relative richness (i.e. making more than your neighbours) and social relevance (i.e. people needing you) will always be more important for building self-worth and long-term happiness.
The OP told that he stayed tough he had other options with probably better options for short term benefits and that he thinks he is happier on the long term. You asked if he doesn't delude himself into thinking that he is happier. I accepted that people delude themselves (all the time one way or the other) but I asked in which situation the self-delusion is "bigger". In the light of your previous comment I don't fully understand your current answer.
(I'm not saying people should stay in uncomfortable situations. But you should be honest with yourself why you want to leave.)