As for tone mapping, I think the examples they show tend way too much towards flat low-local-contrast for my tastes.
I'm a huge fan of Helldivers 2, but playing the game in HDR gives me a headache: the muzzle flash of weapons at high RPMs on a screen that goes to 240hz is basically a continuous flashbang for my eyes.
For a while, No Mans' Sky in HDR mode was basically the color saturation of every planet dialed up to 11.
The only game I've enjoyed at HDR was a port from a console, Returnal. The use of HDR brights was minimalistic and tasteful, often reserved for certain particle effects.
I stopped playing that game for several years, and when I went back to it, the color and brightness had been wrecked to all hell. I have heard that it's received wisdom that gamers complain that HDR modes are "too dark", so perhaps that's part of why they ruined their game's renderer.
Some games that I think currently have good HDR:
* Lies of P
* Hunt: Showdown 1896
* Monster Hunter: World (if you increase the game's color saturation a bit from its default settings)
Some games that had decent-to-good HDR the last time I played them, a few years ago:
* Battlefield 1
* Battlefield V
* Battlefield 2042 (If you're looking for a fun game, I do NOT recommend this one. Also, the previous two are probably chock-full of cheaters these days.)
I found Helldivers 2's HDR mode to have blacks that were WAY too bright. In SDR mode, nighttime in forest areas was dark. In HDR mode? It was as if you were standing in the middle of a field during a full moon.
A lot of people have cheap panels that claim HDR support (read: can display an HDR signal) but have garbage color space coverage, no local dimming, etc. and to them, HDR ends up looking muted.