It's like a contacts card, basically, is how I'm interpreting it. "This person is interesting enough, that I want to keep a private note about them." and then you could categorize each one, according to why they are interesting and how much you want to see of them, instead of having 500+ follows because reasons you can't remember, and all of their notes flooding the timeline indiscriminately, so that you're forced to make lists of "follows I actually _really_ want to follow", to cut down on the noise. 😅

Would also solve for most mutes, as you could have a category "quiet", where they can @ you or reply to your notes, and you can go to their profile and see what they've written, but you don't see everything they post to main.