Folding phones on paper seem to be a great idea, it allows for more resolution of the screen and more area to do things but there’s issues with that. Samsung’s Galaxy Fold phone has this sort of protective film that coverts the screen but if you remove it then the screen dies. Another problem with folding phones is that the hinges or screen could break if you keep it in your back pocket. Having a folding phone also means it’s more fragile so be careful to not drop it. There’s also going to be the issue with cost, having a second screen adds to the price.