You’re in an echo chamber. By default, iPhones do send diagnostic data, but that data can be disabled in Settings. They also upload your files in an encrypted connection (but without end to end encryption) into your iCloud backup, and that can be handed over with a subpoena, but you can disable iCloud backup or simply not pay for it.
Nope. There is data that it sends that is non optional.
Proof: go into settings and disable every tracking options, and then capture traffic from the device through a router with openwrt running tcpdump or wireshark on a computer with a bridge setup with ip forwarding and iptables rule.
Did this experiment already twice to prove to people that Apple device do phone home plenty. Then I repeat the same experiment with my rooted android phone running a custom rom, and people watch the sparse wireshark trace with the only packets being sent are dns then ntp to the android ntp server.
> By default, iPhones do send diagnostic data, but that data can be disabled in Settings.
They also ask during setup and regularly after major updates. I know because I refuse every time. Also, quite often it is opt in, with the box to send information unticked by default.