The point of HDR is to have the ability to go outside the "normal range". this way regular SDR movie won't look dim (or weird), but one that was graded for HDR

The point of HDR is to have the ability to go outside the "normal range". this way regular SDR movie won't look dim (or weird), but one that was graded for HDR can go outside the bounds when it's wanted (and still play decently on a regular SDR display)