Yeah, you can shoot 4K video but how do you get it where you can actually use it?
Use an app called File Sharing Manager. You have to transfer via wifi. You get an IP address and then on your desktop you open a browser to that IP and then tell it where on your hard drive folder you want the files fo go from your iphone or ipad to your PC or MAC.
The bad news is the app annoys the crap out of you with game ads that are difficult to bypass.
An easier one with less annoying popups is "Transfer it" There are actually dozens of wifi transfer aps but I only tried 2 free ones.
What I want is a simple file manager app than can export and import files using the USB to Lightning cable although Transfer it app isn't too slow, just those annoying popup ads.
Then there is the upload to the cloud, like dropbox. Really slow. icloud is there too but I haven't used it for file transfers.