Notes are joined by questions, not bare links. Because supports multiple questioning frameworks - like Socratic, five-whys and Toulmin. Each of these frameworks exposes multiple types of questions that can follow-up on an idea.
Each kind of question is a different way of pressing on a claim: narrowing a term, asking for its cause, asking for support, raising an objection or following the consequence. An idea that has been pushed is much better understood than one that has only been stated.
It also keeps the author honest. A question with no answer is visible as a gap, and a note that never draws any questions probably says too little to be worth publishing.
This is a cool video about this topic that I like.