4K UHD remuxes are basically straight rips of the source Bluray, hence the high bitrate and file size. There are even hybrid remux releases where multiple sour

4K UHD remuxes are basically straight rips of the source Bluray, hence the high bitrate and file size. There are even hybrid remux releases where multiple sources (e.g., WEB and Bluray) are fused together to get the absolute highest quality possible.