Here is a hilariously eye-opening video by Jaggi Vasudev (Sadhguru), an Indian yogi, about why stress management makes no sense. In it, Sadhguru points out that we "manage" things that are important to us. We manage money; we manage relationships; we manage our health. Why would we manage stress?!
Perhaps that most interesting and useful part of the video is that stress is a choice, it does not happen to us. As he jokes - when we are in school we are stressed and want to be working, when we are working we are stressed and wish we didn't have to work, when we are unemployed we are stressed and wish we had a job. If we allow it, we can always find a reason to be stressed. It is our choice to allow stress into our lives. Thankfully, we can also choose to live without it. There is no need to manage something that is of no value to us.