Both have the intent to change and better society. In both you must keep trying and practicing to get and end result and it takes a lot of trial and error. Also, recently theater has been for the rich. This is caused by money-hungry people, but we are trying to better things. There is more art in science.
Creativity is needed in science.
Also some theater techniques are used in psychology. In theater you must know yourself before you assume the role of someone else. This has been used lately by psychologists in therapy. How wonderful and amazing everything is. I wonder how and why things happen the way they do.