You are being naive. An Apple device makes dozens of network requests every minute or so to Apple. It is neigh on impossible to verify what is being requested or sent. Also unplugging the Internet and verifying that something still works does not mean the app won't phone home behind your back when it can. These things are designed to fail silently.
This is Hacker News. Computers are knowable, tractable things. It is trivial to know if a process is making network requests.
Download use Little Snitch or
https://alternativeto.net/software/little-snitch/
https://www.g2.com/products/little-snitch/competitors/altern...
There are many alternatives for trying to find out what’s going on. If you don’t want to bother, and most people don’t, well, what else is there to say?
It is generally a good idea to know what software is phoning home, if you can pinpoint it.
If you have any software recommendations, I’d be happy to know.