Classical note taking tools (analog as well as digital) focus on collecting large amounts of information and not on connecting them. Even though notes can be linked, they usually represent notes on their own and not in the context of other notes.
Mindmaps, concept maps, outlining tools, etc. have their focus on visualizing the relationship in which information stands to each other. Since they usually want to convey the overall picture, they are more suitable for smaller amounts of information.
Zettelkästen do not focus on collecting large amounts of information, but on linking atomic information. They present individual pieces of information in their context. For contexts they use special notes as so-called entry points.