I’ve always found it ridiculous that the content of devices is fair game. There is literally nothing on a phone that couldn’t be digitally downloaded after crossing the border (therefore no “threat” by bringing the phone with you). Similarly, there is no possible way to harm an airplane based on what is present on a laptop; and even if there were, you could buy in-flight WiFi and download the bits after boarding. You could cross the checkpoint with a blank device and in seconds have it populated with whatever you wanted to have. It’s insane.