Amp.pan/Shutterstock Apple discontinued the iPod in 2022, 21 years after introducing the first-generation iPod model, a device that revolutionized the music industry. Now, Gen Z users are flocking to the old gadgets partly because of their big limitation – they can't go online. But that also means they're allowed to be used in places the iPhone is not. The iPhone, of course, inherited the iPod's music-playing features and also supports Apple Music (as do iPads and Macs), a streaming service that generates recurring revenue for Apple. But Gen Z users are now discovering the appeal of a device that can only play music downloaded to it. Apple may no longer be selling iPods, but sales of secondhand devices are surging online, according to reports from Axios, The New York Times, and Associated Press. Many Gen Z users were not born when Apple unveiled the first-generation iPod model, or the various versions that followed, including the iPod Classic, iPod Mini, iPod Shuffle, iPod Nano, and iPod Touch.…