This is very interesting and something I've been playing around with in my head. I keep "chasing the dragon" when it comes to note taking apps/approaches. I've played with everything from NvAlt+SimpleNote (for iOS), Evernote, Notion, Drafts, Editorial, Obsidian, and more. Most recently when I was experimenting with the Zettelkasten notes system (in Obsidian) I got the idea that I would want to do exactly what you talk about and have a "note" per person where I could store trivia, gift ideas, birthdates, etc.
Unfortunately I either don't fully understand Zettelkasten or I am paralyzed by indecision on where I split my notes and how I organize them. I guess I'll just continue using Drafts as my "brain dump"/"all text starts here" until I can find something better that is lightweight and works across iOS/macOS.