If the creative process has timeless principles found throughout history, why aren't they written down and practiced religiously withing our culture that is so enamored of creativity and innovation?

As an example of how this isn't true, we've managed to lose our commonplace tradition and haven't really replaced it with anything useful. Even the evolved practice of the zettelkasten has been created and generally discarded (pun intended) without replacement.

How much of our creative process is reliant on simple imitation, which is a basic human trait? It's typically more often that imitation juxtaposed with other experiences which is the crucible of innovation. How often, if ever, is true innovation in an entirely different domain created? By this I mean innovation outside of the adjacent possible domains from which it stems? Are there any examples of this?

Even my own note taking practice is a mélange of broad imitation of what I read combined with the combinatorial juxtaposition of other ideas in an attempt to create new ideas.

https://en.wikipedia.org/wiki/Life_imitating_art