It also disregards all the secondary and tertiary benefits to "knowing the material" and those benefits of doing the work to get there.

Like honing your ability to research, skills in pulling the actual useful info out of diverse sources of vastly differing quality, speed at which you can pick up new ideas and concepts, etc.

Part of what you're learning is how to do the boring grunt work of learning itself, and honing your skills at that through experience

The most boring days of my job are when I just need to follow well written directions or documentation. The real test is when you're past that and you need to combine multiple things to meet your specific situation, when no one who has figured it out before ever documented it in one easy place.