What is the point of being the head of the department? What is the point of being the head of the department ?


I'm an undergraduate Physics &amp; Mathematics student and I want to stay in academia, do research and also teach. I'm assuming professors also want this. Hence,


Why do they become the head of the department and deal with lots of administrative stuff? 
Isn't that boring for a person who presumably wants to work on his/her field rather than deal with lots of nonsense?


Note: I want to restrict this question to departments in STEM fields only.
I can't speak for the work environments at other schools, but where I teach, the department chair gets an nicer office, a reduced teaching assignment, and extra pay, in addition to some political and financial power associated with the fancier job title.