Note that bigger PIDs like laptops or tablets can also be a hazard.
Also both the EU and US give aircraft operators control over requiring device radios to be deactivated (with the exception of cell service in the US, as mandated by the FCC), as long as they show the aircraft can operate safely.
Maybe it potentially interferes with other radio signals used for various systems during to takeoff/landing.
I thought I’d also read it was just precautionary and wasn’t really necessary and that some airlines no longer require it
It doesn’t. They just don’t want you distracted during takeoff or landing.
Note that bigger PIDs like laptops or tablets can also be a hazard.
Also both the EU and US give aircraft operators control over requiring device radios to be deactivated (with the exception of cell service in the US, as mandated by the FCC), as long as they show the aircraft can operate safely.