Flip phones are making a comeback, but most US adults aren't convinced enough to upgrade.  Smartphone brands are trying new phone concepts, like flip and  foldable phones,  to give us a bigger screen when we want it, while still maintaining the same functionality as the smartphones we're used to. There's the Samsung Galaxy Z Fold 7 , for instance, and there's even a rumor that Apple plans to release its first foldable phone .  And if you remember the popular 2000s Motorola Razr, now there are rumors about the  Motorola Razr 2026 -- it reminds me of my old pink phone. But gone are the days of a basic keypad and a few ringtones. Smartphone brands are adding AI features, such as creating custom emoji, removing background objects from photos, and live translation.  Yet a recent CNET survey says smartphone users aren't sufficiently impressed by new features and concepts to consider upgrading their phones. Only 12% are motivated by AI integrations and 13% by new phone designs.…