That's a fair criticism, although once you learn how to access the documentation and where to look for/expext it I find that most things, including add-on packages and whatnot, can be learned from within Emacs itself just fine. But it does take some knowledge to get to that point in the first place for sure.

One thing that greatly helped this in the DOS / early Windows era was standardizing on F1 being the key for "online help" (meaning, usually, a hyperlinked document that shipped with the product). That was basically the only thing you had to know to start learning any app.

I think is not fair at all, as a default installation has a menu bar, and you can save a file in file->save. While doing so it will tell you the shortcut.