Comment by brotherhoodZero

I’m pretty sure it’s not pocket lint in my case. The loosening happens even on laptops and tablets. The problem is the male part of the connector is inside the device. And it’s quite thin compared to lightning. You move the device around while it’s plugged in and it puts strain on that thin male part of the connector. Next thing you know, the cable visibly can wiggle up and down when plugged in.