logseq is open source, but you gotta pay for (e2ee) sync. Joplin is open source and you can do e2ee with a joplin server or s3 backed. I didn't care for Obsidian. logseq for me.
Paying for sync is absolutely fine as long as the client is open source. Thanks for the logseq recommendation, it looks very good from the first sight! I only wish they had NeoVim plugin like Obsidian has.
Agreed, I pay for logseq sync. Down below someone mentioned doing it with sync thing, but paying is easier for me, and supports development to boot. There is a logseq plugin for vi-like keybindings, but predictably, it's just meh. Hope you enjoy logseq, it's amazing.
I have never used this, but for NeoVim it looks like you might be able to use this (or hack on it a bit to make it work with LogSeq a bit better) https://github.com/artempyanykh/marksman