Think about the request from air crew to switch phones to the flight mode. Many people assume it’s for safety reasons. In fact would it be dangerous for the airplane systems there will be a real measures in place which are enforcing the rule - like a kill switch for all phones, scanners for not turned off devices, collecting devices before boarding a plane; but nothing like that in place. It’s because this particular request is to reinforce that passengers must comply with air crew orders, regardless of what they request (to some reasonable boundaries of course)