I don't really use obsidian as I already have a very capable markdown editor set up in neovim; but it's a nice live-preview editor for my worldbuilding project where I now basically have an internal wiki because it's been 6 years since I started and some things have gotten way out of hand.

it's not that great for the purpose as I've thrown it into an astro project and it doesn't do full HTML rendering; but it's plugins (like dataview) are insanely cool and they will no doubt be indispensible when I manage to make it do calendar conversion math (for which I wrote a quick tool in rust because I was horrendous at doing the math manually)