Markor + Syncthing is the best you're going to get for extremely simple notes with p2p syncing on all your devices.
Markor is a great balance of "as simple as you want + it actually does a lot of shit if you prefer"
All comments on this thread failed to suggest a decent note-taking app that isn't super convoluted.
I used Telegram as a way to quick jot notes for future use, reminders and whatnot, but I am trying to move out of that, so I started using https://simplenote.com/, but what a weird app. It logs me out if I don't use it for like 2 days, I don't like the fact that it has these titles because I don't need titles, I just need a place to paste content, and also it's not chronological like Telegram messages but also I can't reorder the notes as I wish, they are shown by most recent updated first, which is weird.
Anyway, all of that was ok if it wasn't for the weird syncing issues that started to happen recently: it takes sometimes hours for updates made in one device to be synced to other devices, I don't know, it looks like their server is broken or something.
I don't know why I'm writing this note anymore, but I think we could easily have a note-taking app with private notes writing to private relays on Nostr.
Discussion
This is my setup as well. I also use Zim on my desktop on the same synched files. It is not perfect but food enough.
Vim on desktop for me. Bound to a hotkey to open my "working-memory.txt" synced file. Its lovely
And for everything else: Obsidian
I want just the simple. Markor is like what, a full-fledged filesystem with Markdown support and a bunch of other things in a directory-like structure? No, that's not at all what I need.
I like Syncthing, but just turning it on and off whenever I write a single word in my note-taking app feels very bad.
Something's gotta turn on and off to sync (as you know, I know).
Markor has an optional directory system, yes. But you can also just have one single file in one folder, name it note.txt and sync it. Ignore markdown if you like.
Or it's just not for you, and that's aight too :)
Have you tried Joplin?