I would recommend https://standardnotes.org/ after trying all other (OneNote, Boostnote, QOwnNotes, etc.) note taking SWs. Encrypted linked storage (S3, Dropbox, ...) for files, encrypted notes, multiplatform, multiple editors (code, 2FA, markdown, spreadsheets, your own!, ...) & can be self hosted. Easy (also encrypted) backups. I only miss the diagrams tool (like draw.io) or handwriting (touch/pen) support.
I was a Standard Notes user, including a premium plan, but recently switched to Joplin and I've been very happy with it.
I like Standard Notes' no-nonsense business model, with the downside that the free version is heavily feature-crippled (not even a Markdown editor, just plain text).
The Standard Notes server is self-hostable, but it requires a dedicated backend server [0] which was more hassle than I wanted to deal with. Joplin integrates much more nicely with Syncthing for self-hosted but still peer-to-peer replication.
The reason to use Standard Notes, IMO, is the zero-knowledge encryption. I’ll check out Joplin and the others I’m learning about in this thread but I’m happy with Standard Notes at the moment though.
Yes. There is a CloudLink extension for saving the history & notes itself I think, which supports Dropbox, Google Drive & OneDrive. Backup can be also sent daily by the email. And then there is a FileSafe for files - you will simply generate the key (there's a button for it) and upload you files, which will be offline encrypted and then uploaded to your configured cloud storage - Dropbox, Google Drive, WebDAV, AWS S3. The size is currently limited to 50MB (because of the offline encryption).
