Not only is it 'a thing' but these days it's everywhere, even prosumer.
That's not for delivering 8K res selfies, but it's usually for pro production to be able to get 4K (or even just HD) quality vision out of a frame by zooming.
But even pro 16K video cameras are starting to become available in prototypes in Japan. Ikegami and NHK have them and the 2020 Olympics will be full of them.
Trust me, a Terabyte of RAM is nothing if you're editing that footage.
Biting the hand that feeds IT
