[semi-extrinsic]

I get that > 1080p makes sense for text and vector graphics. But really, what are you realistically going to watch on your phone that's been filmed with a 4K camera and optics that match that resolution? The fact that phones are shipping with 4k video capability does not mean the quality is better than the same camera shooting 1080p, especially when you take into account the limit on bandwidth in the encoder chip, so 1080p can be recorded at a higher bitrate.

[ZeroGravitas]

I remember with previous size jumps, it gets to a certain point when you want to be able to decode 4k video, even if your display (or eyeballs) can't handle it, just because that's easier than transcoding the original file.