Regional pricing exists. The cheapest plan is $2 in some countries.

There’s also GoToSocial which is made to be lightweight from the get go.

I already use proton on PC, I needed one for mobile as well hence Calyx caught my eye.

(ProtonVPN’s free plan is limited to one device at a time, that’s why)

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.