iPhones don't even turn wifi/bluetooth off when you toggle them specifically. They certainly don't disconnect in airplane mode.
The quick wifi/bluetooth buttons are to disconnect temporarily when you've got a bad connection. Or if your husband started the car but you're not in it, you're just nearby. They're not to turn the radios off.
Devices are so smart these days that the difference is often lost on users. As you wrote, the button is merely interpreted as a request to not initiate connections. It doesn't actually affect the radio power state and is interpreted quite loosely on both Android and iOS.
When I turn on airplane mode it turns off everything but of course I can turn wifi on just after. But all the phones I have seen when you set in airplane mode it turns off cell wifi BT even nfc