There appears to be a lot of confusion over the purpose of HDR and the benefits of the different formats available.
HDR, or high-dynamic range, is a feature that offers brighter highlights and a wider range of color detail, for a punchier image overall. HDR expands the range of both contrast and color significantly. Bright parts of the image can get much brighter, so the image seems to have more "depth." The number of colors is expanded, displaying additional bright blues, greens, reds, and everything in between.
HDR-compatible TVs are now common. Nearly all midrange and high-end TVs are equipped with HDR and many shows and movies make use of this technology.
There are several versions of HDR competing against each other. While each format works in slightly different ways, their end goal is very much the same. They try to deliver what the human vision is capable of detecting. HDR, HDR10, HLG and Dolby Vision can all co-exist however the market determines ultimately what happens next. At this point HDR10 is in the best position because most devices and content providers support it.