I tried CodiMD, HedgeDoc, Jooplin, Standard Notes, Trillium and a few others.
- Use Markdown or plaintext for notes. This way they are easy to edit and display in almost everything. Don't render anything automatically for me if i don't want to (Trillium im looking at you FFS). - Let me use folders (im looking at you CodiMD, Hedgedoc, ...) - who in the world doesn't want to organize notes in any way? I don't need graphs or LaTeX, i need folders and tags and references and ways to organize myself. - Offer a Web Editor with proper account and user management (CodiMD, HedgeDoc, ...) and a custom landing page if you offer one at all. Let me setup accounts for other people and let me choose who i want to share notes with and who can edit them - just like nextcloud does. I dont need a Web Editor but its a really nice feature so why not implement it in a useful way that its actually managable? - Let me share notes online. Let me generate a Link that i can send others. Let them either enter a password or make it possible to revoke the link and genereate a new one or set a time limit for sharing. Bonus points if the notes are stored encrypted and are shared E2E with the password in the URL just like Mega did. I wouldn't even need a Web Editor if i got this instead. (- Dont use some over the top database structure or framework if not needed)
I feel like most of those note taking app creators dont even use their own product. Also i dont care about a fancy looking UI that uses 8GB of RAM and takes 10 Seconds to load, just make it work.