4K images can be processed, cropped, treated and then downsized to 1080P which looks "much better" than the FHD straight out of camera.......just that alone is why utube Vloggers are using it more and more. Whether you decide that you need that extra IQ for weddings is another matter.
I was under the impression that Sony, Fuji and Panasonic have every decent video AF-C, some with both eye and face detect.
Anyway, although the sale 4K TVs got off to a mediocre start.....it's on it's way, (looking at TV prices, a 4K television can be bought for €500-600 base price for a 101 cm sized screen).
Given the track record of the TV manufacturing industry, I would be surprised if the ordinary 1080P (2 Mb) TV will still be available for sale in a few years time and at ever reduced pricing, who would want one?
I'm no video man either, but the rear screens on DSLRs are rarely bright enough for filming outdoors and most serious bloggers want to be able to look through a viewfinder, of course this means an electronic one.......... a ML camera has all the necessities for video that the DSLR just hasn't.
In the struggle of camera type dominance, the one area where the battle is won is in ML video, and with the Sony A9 competing at sports and kicking butt, things are on the move for stills.
However the death throws of the passing DSLR will be a long drawn out affair, probably painful to watch....but it's on it's way, along with the common usage of 4K!