I have often wondered about this as I am also drawn to be triggered at times.
My conclusion for myself is:
I have no skill in identifying emotions and emotional changes within ... thus, the internal angst and stress rises and rises until it is unbearable and at the point of unbearable I become aware of it and I need to create some equilibrium quickly .... easiest way - get triggered; shake, sob, shout ..... let it all out .... basically create equilibrium. When I am more aware of my emotional state and talking about how I am doing every day, I find I have no need for this .... my theory, still testing it out.
Another thought:
In order to understand and make sense of our trauma, we must relive it .....or so we think.
It is how we hope to come to some new conclusion, some new understanding or insight into out pain, how we hope to finally understand the actions of our abusers or how we hope to finally conclude that we deserve or do not deserve the pain. I used to allow triggers so that I could observe myself, my thought patterns, my advancing panic ... to try to put some words to it, or perhaps some emotions.
I always hope that I will come up with solutions, some new answers ... guess what? ... nothing new .... it's just a thought habit to rethink everything, relive everything in hope that it ends differently the next time.