I believe flight mode actually works, but people with wifi-only devices have been conditioned to believe disabling wifi is sufficient.

And with Apple now being inconsistent about what a on/off toggle actually does... It's hard to tell what toggling flight-mode actually results in.

And if I were in the airline business, I would take an issue with that.

I am actually quite surprised by this and to me it looks like people are just overcomplicating things. You get on a plane, you turn on Airplane Mode. Simple. It would never ever occur to me in a million years to turn on Airplane Mode on my phone, but then go ahead and just turn off the wifi on my iPad. Also, isn't Bluetooth also supposed to be off, which Airplane Mode would take care of?

EDIT: This is what Airplane Mode looks like https://i.imgur.com/mEMYdL6.jpg https://i.imgur.com/4L3uZmm.jpg

As an opposing viewpoint, turning off wifi is exactly what I used to do when boarding a plane - my bluetooth radio is always off.