Japanese television recently launched their 4k/8k broadcasting last month, here's a same frame comparison between a 1080p HD version and the 4k HDR version:
1080p:
4K HDR:
note: delete the last letter ("h") on the image name to get the original size.
None of the three methods in the tonemap plugin I've tested can map the 4k one to look like 1080 one. They all failed on the color mapping.