~90Mbps? That's super high. Admittedly, I haven't been in the shiny round disc game for more than a decade and a half, so maybe they bumped up the bitrate for 4K content??? According to Sony[0], up to 100Mbps is supported. This is just way higher than anything I had ever played with, and find it difficult to think that HEVC would even need that bitrate. Seems like the same logic in using gold Monster cables makes the audio sound better when using such a high video bitrate.
[0]https://www.sony.com/electronics/support/articles/00190648