Passwords in a notebook are arguably the most secure option. The notebook exists in exactly one place, behind locked doors, and cannot be leaked or hacked externally.

Notionally a password manager is more secure, but is there anything stopping Bitwarden from updating the app to silently send your master password up to the mothership and selling your unencrypted vault? Even supposing they stay open source and get caught, they will still have thousands of user's data ready to sell before the rug is pulled and the game collapses.

(And besides, where do you keep your recovery codes? If some cabinet or drawer in your house is safe enough for that, it's safe enough for your book of passwords.)