Well, it should be! 
The other obvious advantage (and I do this constantly while developing) is to go and see what a particular function actually does in the engine. I may not always understand it of course, but it’s so much better than being limited by whatever API documentation exists. Not to mention I can just do a solution-wide search (find references) and see if that functionality has been implemented in other places to learn how Epic uses it. It’s very empowering.