The specific barrier preventing me from entering teaching is the fear of 'teaching to the test'. As you know, in education this means prioritizing a student's ability to answer test questions ahead of other concerns. People approaching the point of getting to know me - let's call them 'ascending acquaintances' - will often suggest I become a teacher, but they overlook 'teaching to the test', and my fear that it would pull me away from bringing out the best of my students. If you are clueless about math, my interest is to help you get a clue, not pass the state's geometry exam.
But isn't knowing how to pass a test a useful life skill? It might be in a situational sense, but I suspect knowing how to make the best of a bad situation temps us to do less about changing the situation. I think our current moment is an interesting example. As our cities and towns start to reopen, health officials are measuring progress by monitoring a handful of important metrics. It's a small concern, but not a trivial one - we'll reopen either when it's safe to do so, or when folks figure out how to game the metrics. Now reader, you may be scratching your head - where could anyone have learned the skill of passing a test, just to mask an underlying lack of qualifications? It won't ever be from me.