So what happens when you get a cell phone call or text? That's chargeable cell service.
I agree with you. I use my Win 11 laptop all the time. On a laptop Airplane Mode means no WiFi. We are saying the same thing. but with subtleties, many won't understand.
Just a caution, too many people will try this on a cell phone, and won't read your entire post about turning things off on your cell phone. You are technical, but most aren't, when you say just turn off data that's great, but you can still get a call or text. It's much better to just turn off roaming on your cell phone.