The definition of "fundamentals" differs though, depending on how abstract you get. The more layers of abstraction, the more abstract the fundamentals. If my goal is high-level programming, I don't need to know how to write code on bare metal.

That's why I advocate breaking things down until you reach the level of triviality for you personally. Most people will find, "writing a for-loop" to be trivial, without having to go farther down the rabbit hole. At a certain point, breaking things down too far actually makes things less trivial.