I use it ho properly disconnect from mobile network, if something not working with it on iPhone, disabling and enable mobile network did not do the trick, don’t know exactly why.

Because the cellular tower icon disables mobile data, but not the radios. You can tell because when you turn it off you’ll still see bars (if, you know, the radio is working).

Airplane mode on iOS disables cellular radios, but leaves WiFi and Bluetooth on. Your phone will sit there blazing (figuratively) as bright as the sun in its cellular radio spectrums trying to hit a tower when you’re 35,000 feet up, eating up your battery and potentially fucking with cell towers as you fly overhead, where WiFi and Bluetooth won’t. It also prevents potential interference from the 2G radio with the ILS the plane uses for landing (as I saw elsewhere from a pilot).