Yup, difficult to watch hd channels on 4k
tv unless its some news channel.
On a 4k tv, viewing a 2k digital intermediate movie in a 4k blu ray release has some advantages.
a. Upscaling has already be done accurately, instead of by 4k TV processor doing the upscaling on the fly.
b. Hdr. 10 bit color. (Color range is also supposed to be better. But I don't know its details.)
Even if one gets a 4k laser projector
, and sets up a dedicated room, I'm not sure if the digital cinema package thingy (high bitrate ones) are commercially available, or how much it costs.
-edit 1--
Regarding the minimum bitrate, i feel it depends on the encode as well. Eg a movie encoded at slow settings, 18 CRF quality (
variable bitrate) , on x265 codec, will be equivalent to the Blu-ray (~ 70-90 mbps). If one enables statistics while playing it on say a vlc player, you can see the uncompressed video bitrate go about 40mbps for extremely fast action scenes with a lot of background movement. Even the most ardent movie connoisseur would struggle to notice the difference on a 55' home tv.
Not sure about giant 100+ inch projectors though.
