4K is common in TV production. In my experience lossy compression is a big no-no in TV and they do edit 4K losslessly, although in order to transfer it they generally split it as 4 times 3G links (either interleaving the pixels or generating a 2x2 mosaic). 12G links exist but 4x3G is still vastly more popular due to being backward compatible with existing equipment. Color correction, scaling, blending and compositing are all generally done with uncompressed video.
Of course once mastered the video gets heavily compressed to be sent to the consumers.
Ok I shouldn't use the word nobody, I admonished someone for using that word a few days ago, but it's very rare, especially outside high end production houses.
Even 12G sdi is compressed - we consider 4:2:2 and 10bit uncompressed, but 4:4:4 is less compressed than 4:2:2. Once you go into interlace or stupid things like 24p you're throwing away tons of data.
2022-6 seems to be the transmission method of choice so far, 2110 may well take over, but there are significant compatibility issues.
Personally I'd prefer everything originated as 4:4:4 10 bit 150fps (no drop frames), resolution I'm less concerned with.
I work in news though, broadcast quality is what we broadcast. 5mbit h264 PPP with a vbv of 200k is fine for a talking head internationally. 5 times that is plenty for an actual broadcast program with astons and stuff.
Setting aside high end production houses. Even then things aiming for TV get compressed to a mezzanine format that's heavily compressed (in comparison), then compressed again for TX
