You got 720p,1080p, 4k. More pixels. Doesnt take a fuckin brain genius to figure out if your tv's picture looks better because of course it does, and you don't gotta do anything to get it to work. but they realized that past 4k, shit ain't gonna look much better for the cost. so what do they do? more colors per pixel. only problem is color settings on tvs suck. tv manufactures handle this like dogshit. so now you gotta spend 30 minutes before watching a movie cause your fuckin tv automatically changes the setting from time to time for no fuckin reason. all this just to get slightly more colors. it's not even that noticeable. i fuckin hate HDR. i fuckin hate tv manufacturers.
the shining's still a beautiful movie but fuck me did i not notice the HDR one bit.
There are few games I notice any substantial difference with HDR on vs off.
I will say however, check out Ori and the Blind Forest: Will of the Wisp with HDR on. God damn is that not the most beautiful damn colorful HDR experience I have ever seen. Absolutely worth it just for that. Besides, its a new standard, no one should go out and buy a new tv just for HDR. Buy it because it can provide a better experience, sure, in whatever fashion you'd like it to do that. Just don't waste money thinking its some selling point apart from a couple of games and the possibility of new amazing experiences.