99.9% of people expect HDR content to get capped / tone-mapped to their display's brightness setting.
That way, HDR content is just magically better. I think this is already how HDR works on non-HDR displays?
For the 0.01% of people who want something different, it should be a toggle.
Unfortunately I think this is either (A) amateur enshittification like with their keyboards 10 years ago, or (B) Apple specifically likes how it works since it forces you to see their "XDR tech" even though it's a horrible experience day to day.