[sirclueless]

This is actually a good reason to move away from pixel designs and towards vector graphics. An assumption made now is that there is one or maybe two resolutions at which a 128x128 icon is displayed, and this is true for iOS screens. But with a more heterogenous selection of screen resolutions and expected screen distances, the actual display size of a 128x128 icon is basically unknown.

There are two problems you are conflating. One is that low-resolution icons have visual artifacts, and therefore manual pixel hinting is valuable. In general though, this problem only crops up for very small icons, say smaller than 32x32. But as screen resolutions increase, this problem will get easier.

The other problem is that at small sizes, we want icons to be less detailed and therefore more recognizable. A quarter-inch icon two feet from the eyes should have very little detail. This is a problem that vector graphics are very suited for. One can specify a low-detail icon that should be used when the real size of the icon is below some threshold, no matter whether that screen space is 64x64 or 20x20. In a world where the screen resolution of an icon that size can vary by more than a factor of two, using pixels is the wrong approach.