I've used Obsidian for a couple of years, mostly for private to-do things
I used iCloud to sync between phone and laptop.
It worked great until recently.
Now I experience extreme jankiness: App sometimes takes forever to load, files missing, or suddenly disappearing as I open them. The problem, as far as I can read, is iCloud aggressively removing files locally when they're not used. I haven't tried Obsidian Sync yet.