Dark scenes don't compress well. You get tons of banding and blocking and artifacts in dark scenes.
You also have to control the ambient lighting around the TV which can be a pain in the ass.
If directors want movies to be seen, they should consider the home viewing environment. Just as the article says many films consider the home sound environment and mixing for non-pristine environments.
Having watched all of Game of Thrones on Blueray, when the final season came out I was stuck with a UK streaming service called "nowtv", which my router reported was pulling in at 4mbit a second.
Given that was specifically filmed to be streamed, it's amazing how poorly the director considered what the streamed, compressed version would look like. Or that HBO didn't insist on something that would stream better.
Was it? I thought HBO was a cable channel, which of course is streamed and compressed, but TV has always been streamed and compressed (even in analog days - 422 is compression standard as it throws away a ton of chroma, interlacing is compression as it throws away half the data, both rely on the brain to recover), so I assume you're talking about unicast streaming.
I'm sure it would have looked fine if it was streaming at 20mbit.
In the UK, the DPP sets contribution bitrates for close-to-tx programs* HD are 45mbit h264 or 60mbit mpeg2 for live contribution, if you have to compress it (clearly 1.5gbit is preferred), and for UHD I think it's 90Mbit h265. Those bitrates are set to assume another compression layer, but I suspect if that episode had gone out on say BBC One HD it would have been running at 15mbit+ for the entire time.
* Game of Thrones I suspect would be classed as a close-to-tx delviery to reduce chances of leaks - certainly I know a broadcaster in Austrialia was receiving it on an NTT decoder over an MPLS from their LA office rather than as a file)
Now TV is owned by a traditional premium broadcaster called Sky. I'm pretty sure they deliberately handicap the service, so as not to cannibalise their more expensive traditional packages.
You also have to control the ambient lighting around the TV which can be a pain in the ass.
If directors want movies to be seen, they should consider the home viewing environment. Just as the article says many films consider the home sound environment and mixing for non-pristine environments.