Systems which are designed to free up cognitive resources—like the Zettelkasten method for note-taking or the Getting Things Done personal productivity system—must take a comprehensive view of the activity for which they are designed. You need to be able to really trust that everything from the smallest details up is properly handled before the system can free up your working memory to focus on the task at hand and get to the state David Allen calls “a mind like water”.
These systems are structures that we can use to work around the distractions imposed by our own minds. It’s a common experience (so common, in fact, that it has a name: the Zeigarnik effect) that, when sitting down to do focused work, our minds bombard us with smaller tasks that are less cognitively demanding (and often less important). This is the key benefit of Getting Things Done, and is also one of the promises of the Zettelkasten method for note-taking.
In How to Take Smart Notes, Ahrens states that the Zettelkasten really is analogous to GTD but adapted for the less linear process of writing.
References
Ahrens, Sönke. How to Take Smart Notes.