Pros

End-to-End Encrypted as long as you enable it in your iCloud Settings via Advanced Data Protection.
Can edit PDFs inline with iOS 17.
Quick notes on Apple devices from anywhere are super useful.
Can draw/write with Apple Pencil and it works wonders.
Free and built into the OS.
Easy to collaborate on shared notes and folders.
Siri can create notes or append to existing notes.
Bi-directional linking so you can link notes to each other as another way to find them (iOS 17).
Rich text formatting to make it easier to format your notes.

Cons

Basically unusable on Windows/web.
Unable to paste code as it does not have code blocks. Only “monospaced” font (iOS 17) which adds a different background but doesn’t function as a code block.
Only so much formatting that is available.