Mona Lisa is also "dated", so what? ;-) If you develop something close to perfection, there's not much to change. Of course, you can do changes for the sake of changes, or pretend to build "new stuff" by changing irrelevant details, or make a big change and go further from, rather than closer to, that perfection.
Why would I need a thinner phone? Should a phone bend / brake if you sit on it in your pocket? Or you want to use it to cut cheese if you forget your knife? I prefer more battery life if the rest of electronics frees some space due to miniaturization. As far as ceramics is concerned, yeah, looks hipster enough, but it is also very practical in case you happen to drop the phone ;-)