ObsidianMD

One vault keeps my list of games to play, things to read, etc. for later. I have it set up a particular way for quick and easy entry with the Meta Bind plugin, and DataView for easy listing of everything (each piece of media to consume is a separate note with tags according to things like genre, subject matter, etc. and DataView sorts on those). This gets a whole vault to itself because of how every piece of media is a separate note: not much information in one one; when I usually have one note with a lot of stuff in it. This would absolutely clog any other vault. It also gets a whole vault to itself because I have no need for DataView or Meta Bind at the moment in my other vaults. My other vaults are plugin-free.

I also have a vault for storing notes on my personal creative projects, whether it be a long-abandoned attempt at planning a TTRPG campaign or a video game.

One for academic notes. I also have a separate math vault that did not end up getting very far, intended to help me review a bunch of math I already learned (and maybe to one day share to help teach others), maybe I'll pick it up again.

Finally, I have a sort of catch-all vault for everything else in my life I might want in Obsidian. This is my most frequently used. It's where my recipes live, where information about myself I should probably know about myself but often forget lives (like the exact day I moved into a different house), where I keep track of knitting patterns and my progress on them…

This is not how you are "supposed" to do it, I always see advice to keep everything in one vault, but this is what works for me.

Thanks for posting this question!