Foldables opened the door to a whole new world of smartphones just a few years ago, but somehow the entire Android market has settled into just two form factors – clamshell flip phones and book-style devices that just open up to double the width of a normal smartphone screen. As the inevitable “iPhone Fold” approaches, though, it seems Apple is looking to revive a form factor that Android brands, including Google Pixel, once tried, but failed to keep around, and there’s a clear reason why that happened.