[bitL]

How far do you hold your phone from the eyes? Now compare it to your regular TV - how far do you watch it from? With 55" 4k UHD you'd get retina-style appearance from 1.5m upwards.

[vidarh]

Two issues with that:

For movie watching people keep wanting bigger screens. You can buy 80" TV's, and then come projectors.

Secondly, my main screen use is for monitors, where I am only about twice the distance away from how I typically hold my phone.