Dragon Ball Z

Here's what I don't get about Dragon Ball Z. They have flying cars, Flying People, People who can shoot energy from their hands, Green slug people, Saiyans who get stronger everytime they almost die, A magical wish granting dragon that is summoned when all eight dragon balls are summoned, People who can teleport, Time travel, Saiyans who can breathe in space and be under water for more than 5 minutes, a capsule that can hold anything and MANY more impossible things. But they all use flip phones. They don't go touch screen until Dragon Ball super.