[csydas]

Precisely. With any outgoing connection, your phone is constantly looking, reporting, and talking. IIRC, didn't Google (or maybe even some Open Initiative) do a huge mapping of routers based just on the MAC and overlays with GoogleMaps or OpenStreet?

A connection exposes you to surveillance, and yes, it's worse with SIMs, but having WiFi on just adds a little latency to the same thing. Public Routers that you're discovering do the same thing. I had thought this was the entire point of iOS devices randomizing their MACs when scanning available networks (no idea if this ever got shipped with Android devices).

I am probably in the "nutty" quadrant when it comes to concerns about tracking, surveillance concerns, and online privacy, but I also don't really like needlessly inconveniencing myself just to undermine the entire purpose of why the inconvenience is necessary in the first place. Your phone is always talking -- SIM card or not. I'm not even sure modern non-smart phones (flip revivals and such) are wifi free.

Such protections are a good ideal, but a lot of people have an unrealistic idea of the threat actors they're trying to protect against.