Question. How do I get the 4K video onto my tv to take advantage of the new 4K video recording? I can't airplay it because my apple tv does not have support for 4K. Upload to my computer and then put onto a flash drive is the only thing that comes to mind...
And there's your main problem. True, the video will play on a 4k or better PC or retina iMac. But that's a vast minority of people that own things like that. For the typical iphone user, they're more likely to have a 4k tv vs a 4k or better desktop.
But the lightning hdmi cable to tv is limited to 1080p. Airplay is limited. Apple tv? Nope. The new ipad pro? Nope. Only plays 1080p. Most will need a capable computer. Most mainstream users will be clueless how to get any iphone 4k video on their 4k tv or more likely be amazed at the still 1080p content streaming that they think is 4k.