@Gargron He is only talking about movies, but especially Netflix has some strong requirements for its production contractors about specific 4K cameras and CGI + editing in 4K in series. They want grounded reasons to upsell you to their 4K plan, so 4K series on Netflix and Prime are usually true 4K productions with a complete 4K DI pipeline.
Newer cinema movies of the past, say 6 years, also do often have whole 4K production pipelines (just don’t expect it from Disney).