What an incredible question! I am awed by your sense of selflessness in being prepared to give up a job that you love because you feel that someone else could do a better job. It is very hard for me to advise the best course of action without knowing you personally, but I would actually say that perhaps you should remain in your job and continue striving to do the very best job that you can do.
Why? I have two reasons. The first is that someone who feels that things could be better is someone who will try that little bit harder. That is an incredible plus both for the school that they work for and for the person.
However, I think that there is another dimension at play as well, and that is we are not put into this world to live a life of tranquillity. We are here to toil and to strive to reach further upwards towards God. Tranquillity is a dream that when lived allows a person to lose their desire to achieve new things and to continue growing. Tranquillity lets a person stagnate and to become frozen in a moment of time. That seems to me to be the most compelling reason for you to remain in your present position. Although it will mean hard work and a continuous struggle to succeed, may God assist you to continue flourishing and growing and achieve great success in your important efforts!
