The problem with OneNote is that its file format is proprietary (though documented). I have random notes that are 20 years old. Notes I take today need to be readable 20 years from now. Will OneNote be around 20 years from now? I prefer to store my notes in plain text because it is guaranteed to be readable decades from now.
Do you intend to restore today's backup of your OneNote files with a copy of OneNote 2039? It might work or might not.
But if you keep using OneNote for the next 20 years, I can guarantee that it won't suddenly implode and suddently make all your notes unreadable by anything else.
You can export an entire notebook, or individual notes to PDF. PDF is easily converted to text so there is one way to archive.
I had stopped using Apple Notes because the format was a proprietary binary format with no export feature. When I found an app to export as text I went back to using Notes.
