I'm even more intrigued by the whole family sharing two phones and switching sim cards. What's the reason behind it? How does it work?
It's vanishingly rare for me. I got a call from a friend today - but I think I otherwise only make or receive a legit phone call every few days. We use social media mostly. Work "calls" are on apps.
A family could probably get away with 2 phones easily, as long as they have home internet.
Now... When I was young and internet was over dial-up, having a single phone line for our whole family caused quite a lot of spats.