A lot of people think that traditional note-taking can be improved (me included). As evidence, below is a short list of note-taking companies that YC has recently given money to.

Clover: https://www.ycombinator.com/companies/clover

Athens: https://www.ycombinator.com/companies/athens-research

Dendron: https://www.ycombinator.com/companies/dendron

Heptabase: https://www.ycombinator.com/companies/heptabase

My current favourite tool is the whiteboard feature of Diagrams.net (https://sketch.diagrams.net/). It is similar to the philosophy of Heptabase, which is centred around organizing notes and images with a whiteboard. But I like the openness and portability of Diagrams.net (Although I'm a big fan of the Heptabase team and product!).

I organize my notes in an outline/mind-map style similar to Amazing Marvin (https://amazingmarvin.com/) left to right connection is parent to child while top to down connection is older sibling to younger sibling.