You don’t need internet to access the passwords stored in Bitwarden if you have their local clients installed. It stores an encrypted copy of your database locally to your device which syncs (updates) over the internet.

I’m sorry if I sound naive but what’s wrong with using a mobile?

I thought people use traditional music players like iPod and Tangara only because of their retro feel, is there something else to it?

There’s also https://justbeamit.com which iirc also functions in a similar way.