I agree with you in general, but one important aspect of "HDR" is 10+ color processing (not necessarily showing, FRC8+2 is already an improvement) on the displays. That lets you create more grays etc
Yeah, I considered rewriting to try and use colors as percentages and show the idiv x/256 banding problem of hexadecimal colors, but for today's purposes, I will be satisfied if I inspire long-time web programmers to start realizing that sRGB hex is a dead end way to think about color. It was enough to discuss the problem of peak luminosity being greater than 100% sRGB luminosity and I couldn't find any way to do a better job at the one without doing a worse job at both.