I use it for most of my note needs (random things I need to remember, TODO list for what to buy tomorrow, steps for a project I want to finish, the guide to resolve that stupid bug in Linux next time I hit it, etc...).

I like that it's in markdown so it's easy to switch to another tool later if I need to. I don't use the Obsidian Sync, but I just use Syncthing to sync the folders across my devices (including phone). I also have Obsidian app on my phone and that's generally ok, just a bit cumbersome sometimes.