This is beautifully expressed. Knowledge consists of connections across concepts but those connections are rarely shown explicitly in textbooks. Even wikipedia, while allowing you to traverse the connections back and forth easily, does not do a great job of giving you the bird's eye view of a subject or a field. Check out this "map" of mathematics: https://www.youtube.com/watch?v=OmJ-4B-mS-Y Every subject needs a similar map.
Besides visualizing the connections, we'd also need interactivity to the topic that helps with forming new mental models - which is the core aspect of learning. Jupyter notebooks, ObservableHQ, Mathigon are some of the good projects working on this aspect.
Disclaimer: I am building the open-source project https://github.com/learn-awesome/learn/ which is attempting to build the complete map of knowledge/skills. So I too am biased against books and in favor of digital/interactive tools.