I am searching for the note taking app with the same criteria and right now i am using Cryptee (browser based, no app) and trying to like Joplin. Sometimes Cryptee is slow at startup, but has web app, encrypted, is simple to use and has 2fa. Joplin is fast, supports cloud storage of your choice, but has awful sync issue. When you have some notes uploaded and synced and decide to reinstall the app in your phone and sync it again, your notes will be lost.

If you have the time to learn emacs, its really good for note taking. I don't think any app other than Vim could compete in taking notes in my math class.

I recently started to directly use KeePassDX even for notes (since I sync it with syncthing) and I must say it's very good.

SiYuan (GPL) is probably the most advanced. You can get it off github. I haven't found anything that compares in terms of notes based features. Appflowy and Affine also are open source and have good note taking capabilities.