"Share" is the key word in my rant. I know spotty support exists here and there for one format or another.
The problem is that I can't, in general widely share a HDR image and have it be correctly displayed via ordinary chat applications, social media, email, or what have you. If it works at all, it only works with that One Particular Format in One Specific Scenario.
If you disagree, find me something "trivial", such as a photo sharing site that supports HDR image uploads and those images are viewable as wide-gamut HDR on mobile devices, desktops, etc... without any endpoint ever displaying the image incorrectly such a very dark, very bright, or shifted colors.
Huh? Safari seems to render HDR JPEG XLs without any issues these days (e.g. [1]), and supports wide gamut in even more formats as far a I remember.
[1] https://jpegxl.info/resources/hdr-test-page.html