I’m using Trilium notes. it’s simple enough and does what i need. Used to use Obsidian but wanted something open source, and with Trilium you can self-host the sync server for free (even comes with a handy web-ui).
Note that it is much simpler than obsidian, but for me it’s plenty. It was easy to import my obsidian vault into it, and it allows exporting as .md files which work fine back in obsidian too.
Recently the dev said he’s putting it into maintenance mode, so no new features will come to Trilium. There’s a community around Trilium Next that wants to keep expanding it, but personally i hope Trilium stays as it is and is maintained for a long time.
i’m thinking long term - sure, right now google knowing everything about me isn’t dangerous. but if a massive political slide to the right happens in countries that host services, suddenly all the saved data from many years ago can be used against me. and don’t fall for the “end to end encrypted” bullshit either - all these services can flip a switch and have your encryption keys instantly. (or, if its an open source app that ACTUALLY keeps keys on the device only, which is extremely rare, it’s one update away from happening, and you better read the whole diff every update and compile the app yourself.)
that’s why i choose to self host everything. yes there’s a risk of being hacked, or installing something malicious because i don’t read every diff on every update. but i feel more confortable with it being my own responsibility, and my services are also all on seperate virtual machines to hopefully isolate any breaches.