Was Gage’s skull used for educational purposes that couldn’t be gotten from the information when he was still alive?
Well, when he was alive, he was still using it. That does kinda put a damper on things, from an educational point of view.
And was that worth keeping it for well over a century?
Honestly, yes. At this point in time, Phineas Gage’s skull and the knowledge gleaned from the study of it has been used to educate thousands upon thousands of people, and then each of those multitudes of educated people went on to improve the lives of thousands and thousands of people. That’s pretty damn good for one single cadaver.