Wow, you are not even close on most of your assumptions as to why teachers become teachers and why they quit.
A great majority of teachers become teachers because they enjoy working with young people, they want to serve in a greater cause, and/or they simply love to help others. There is no superiority of information knowledge teaching has nothing to do with that.
Teaching involves breaking down complex ideas and information to simple digestible chunks and then figuring out the best way to deliver it in order for multiple students to learn.
Fundamentally teachers teach because we love to teach. The reason why good teachers quit is a simple cost benefit analysis. I thought you were going to be right about that but the you went into somthing about it being chaotic. It is simple.
When great teachers get thier very small paycheck, or when they get thier very complicated evaluation they ask ‘is it worth it?’ Is trying to teach effectively through all this red tape, for little pay, for no growth opportunity worth it?
When the answer is no they leave for more opportunity. It is always sad to see great teachers leave because the system they are working in does not reward great teaching. There is no reward for being a great teacher so great teachers move on.