@Yongkit
The HDR clips on that YT channel are very likely to be bogus.
View attachment 38660
HDR Playback (left), SDR playback (right).
The deeper blacks are from OLED technology (left) vs IPS (right), and the left side is sharper due to a higher PPI (See the font). While the color balance is slightly different, that is normal due to using different screens and different video timing.
Firstly, the HDR playback didn't have natural HDR-like lighting, and the luminance values peaked about the same. In such a scene, it definitely will not be the same. Both of these factors are dead giveaways. On OLED, it is very easy to tell apart these 'HDR' content.
Many channels simply inject HDR metadata and change bit depth, color space, and max luminance level on SDR clips to register as HDR clips. This will not change the actual dynamic range of the content, leading to an inaccurate representation of HDR.