Dunno if you checked out Obsidian yet, but outside of the features already mentioned, I really like the UI and plugins. You can open multiple notes at once in the same window and organize them how you need which makes referencing multiple notes/topics really easy.
Obsidian is a much better tool for connecting ideas and organizing thoughts, imo. I feel OneNote is a bit easier for anyone familiar with Microsoft products and looking for more of a bulletin board (which Obsidian can do with plugins). But even daily notes and idea dumps feel more productive with Obsidian since it's so much easier to organize everything.
Just my opinions. Hope that helps!
Have you listened to Caligula's Horse?