I generated it using gource https://gource.io/.

It shows where I am active in my collection of notes over a period of time. How new directory structures are born and the parts of my notes that I keep returning to and updating.

It's showing part of my collection of org-mode files over time. Files are the dots at the edge, directories are where the branches are. Most of this visualization is prior to me starting to use org-roam. I started using org-roam back in 2020/2021 but that part of my org-mode files was not tracked under version control until a few months ago, it's obvious in the visualization near the end when a big green bloom is born and quickly grows.

So, it's nothing to do with complexity per say, but volume of files and parts of my notes where I am active over a period of time.

Make more sense?

I use org-mode constantly. I keep a log of what I'm doing each day. I use org-babel quite frequently. I use org-roam for most capturing and finding most notes. If I need to dig deeply I usually use ripgrep. I use mu4e for email in Emacs.

I have a post that I nudge along describing how I use org-mode currently. https://cmdln.org/2023/03/25/how-i-org-in-2023/