Well... Retina on 4.7" device is ok for me, Full HD on 13" laptop is kind of OK but I wouldn't mind even higher resolution on it. High resolution screens do have their benefits, especially on clarity of smaller objects and text.

On cameras, it's not those megapixels per se that cause the need for more CPU-power, but all those other features that actually make the images taken with cameraphones bearable. They use quite a bit of software touchup, not to even mention the DSP power to improve sound quality on videos. Of course you could try to build phone into DSLR but who would carry such a device around? Honestly, last holiday trip to Europe I didn't bother to carry my DSLR with me with all the other stuff already packed to small car with two kids and wife, also quality of videos taken from several concerts are quite good (and I haven't even tried 4k yet).

One thing that surprises me is the urge to stick to everything really old. As if all progress and development was inherently bad and should be avoided at all cost just because in theory it's possible to achive feature X using minimal amount of CPU power, althrough making it work takes considerable amount of human resources and time (not to mention cash). AFAIK last mobile OS created with such mindset was Symbian and that ended up being major PITA for both developers and users.