> When your phone is on 5g it is not behind a strong firewall, or any firewall at all.
I‘d be surprised if that’s true for most operators.
And even if there really is no stateful firewall: On IPv4 you’ll be behind carrier-grade NAT (so no inbound connections), and on IPv6 (including NAT64/DNS64), successfully guessing somebody‘s IP address seems extremely unlikely. (A server that you’ve visited might "dial you back", though.)
And for most users, the most visible effect will probably be that they can’t connect to their Chromecast, smart speakers, AirPrint etc, not decreased security.
I‘d be surprised if that’s true for most operators.
And even if there really is no stateful firewall: On IPv4 you’ll be behind carrier-grade NAT (so no inbound connections), and on IPv6 (including NAT64/DNS64), successfully guessing somebody‘s IP address seems extremely unlikely. (A server that you’ve visited might "dial you back", though.)
And for most users, the most visible effect will probably be that they can’t connect to their Chromecast, smart speakers, AirPrint etc, not decreased security.