HDR should not be "typical web" anything. It's insane that websites are allowed to override my system brightness setting through HDR media. There's so much stuff out there that literally hurts my eyes if I've set my brightness such that pure white (SDR FFFFFF) is a comfortable light level.
I want JXL in web browsers, but without HDR support.
There's nothing stopping browsers from tone mapping[1] those HDR images using your tone mapping preference.
[1]: https://en.wikipedia.org/wiki/Tone_mapping
What does that achieve? Isn't it simpler to just not support HDR than to support HDR but tone map away the HDR effect?
Anyway, which web browsers have a setting to tone map HDR images such that they look like SDR images? (And why should "don't physically hurt my eyes" be an opt-in setting anyway instead of just the default?)