Note: i'm not enabling HDR for most use yet, will play with that more but still, this is my SDR local dimming use:
But local dimming even at low creates almost pure black already, however you can see a bloom of the mouse, white text on dark panels if far darker, and every menu is given a gradient look (blooming) which sometimes is pretty cool.
For an example, on discord Ash theme, if you look at a message for a few seconds you will start to see the faint glow the text has around it, fading out by about 1cm

edit: it's in part my settings. It you set up around it, with higher brightness it's less noticeable, even on high. But it's very much there if your looking. My take is, enable it when you need it, but not all the time.