One thing that is often missing is the art of engineering itself. I started writing code as a kid, and a lot has changed in terms of technologies, syntaxes, paradigms, frameworks, etc. The pieces of the jigsaw puzzle change, but not the art of putting them together. Unfortunately, that art is not always visible, because when someone opens code, they see syntax rather than design.
I think that invisible art is something that gets missed when myopically focusing on specific technologies or frameworks.