A mechanical hinge is going to fail (I’m not talking specifics on phone hinges, but rather any kind of hinge, which also includes the screen itself, since a folded screen has a hinge too). Talk to any mechanical engineer about it. Between Samsung and the few Chinese brands selling hinged phones now are sold in such small numbers at high prices, so you’re not going to hear about failures for a couple of reasons. One, because people will purposely try to be more careful with them and the other is it’s just a smaller pool of users who may not even be using their folding devices as their only device.
And in regards to the screen being damaged, I wasn’t talking about the outer screen, I’m talking about the inner folded screen getting damaged from detritus in your pocket or bag getting between the two sections of the inside panel. The fact that the screen isn’t folding flat on itself (it can’t because you can’t fold glass or even the OLED panel itself with a crease), you have a variable distance between the folded pieces which allows stuff to get between the panel sides.
I believe we’ve hit peak smartphone. What we’re seeing already are iterative advancements year over year, which is why companies brought back folding devices, in an effort to expand the market beyond the current form factor. But doubling the screen size is still going to be limiting to someone who wants an ever bigger screen. With AR done through glasses, your perception of size has almost limitless potential, with no drawback for weight or being able to handle a device comfortably.