So your carrier/sim can also control your WiFi connections. I never added these and they were set to Auto-Join with Private Wi-Fi Address set to Fixed. Cool cool. It's probably used to help balance loads on RAN in places where carrier Wi-Fi is available, but I'm not 100% comfortable with this.

Couldn't a bad actor just set up a Wi-Fi network with these SSIDs and capture the traffic of unsuspecting victims?