When I was an iPhone user, I created a shortcut that automatically turned airplane mode on when I connected to my home Wi-Fi network and one which turned off airplane mode when I disconnected from wifi.
I always have Wi-Fi calling turned on and I'm sure many people do. This would a great privacy feature to allow us to route phone call data through a connection that is "VPN-able".
It might also be nice to add in a selectable airplane mode where I can choose to turn off bluetooth and/or wifi in addition to cellular, or leave either of them on.