Those are the urban ones. The ones in the countryside were useful sometimes if you were trying to get a taxi or a lift. They often had plants growing in them.

And some were in very remote locations. The Nant y Maen phonebox in Wales springs to mind although I think it no longer has a working phone in it.

Some of them were indeed. They were very handy in pre-mobile phone days for when your car broke down, or you had to contact someone.