A lot of good anime are good because they don't put a lot of effort into cutting-edge graphics but on other elements (characters, story, animation, etc) => using 4k and/or HDR might just drive up the costs without providing a real benefit.
And on top of that, some of the technological "advancements" actually make things worse. Personally I loathe the trend towards 3D-rendered "anime", artificially stuttered to make it resemble a hand-drawn animation. The only time such techniques are appropriate is when showing something mechanized. Used on regular characters, it looks terrible. Knights of Sidonia was a great show, but it looked really bad. The visually-best recent animes are ones like Devilman Crybaby that really embrace the hand-drawn medium and run with it.
I agree - for example stuff similar to Evangelion ( https://www.youtube.com/watch?v=mdU8dyjgXU0 ).
A lot of good anime are good because they don't put a lot of effort into cutting-edge graphics but on other elements (characters, story, animation, etc) => using 4k and/or HDR might just drive up the costs without providing a real benefit.