In a situation like what you have described, often the person selected is not necessarily the one that has put in the most effort or proven themselves. There are most likely reasons for the choices made that you have no idea of too. Sometimes it's more of a political or social connection thing where the individuals that got selected have a closer relationship with someone who was making the choice too. It could have even been a choice based on how the individuals needed to be handed something that would boost their self esteem and you were passed over simply because you already had proven yourself to be capable.

That being said, I am going to share a story I had heard, a true story. This man was very good at doing a lot of things, he would get great jobs too, BUT, he could not seem to stay in a job for a long time. He would end up being let go a lot. Then once again he got a really good job and was there for about a year and his boss called him in to tell him that he was being let go. Then his boss said to him, "do you want to know why?".
His boss said, "you are very good at your job, you do your work great too. The problem is that while you do your work great, if others fall behind you end up doing their jobs too. Well, for a while these individuals have been coming to me complaining and they are unhappy about "you" doing their jobs too. So, I am letting you go because I can't have my other employees upset like this."

MAYBE what you did wrong was that you were too proficient. Sometimes that's the problem and not that a person isn't good at doing their job or activity.