This has been supported by both Apple and third party apps for over a decade. I’ve implemented it myself.
Actual HDR needs at least 10 bits per channel and a modern display with peak brightness far in excess of traditional monitors. Ideally over 1,000 nits compared to typical LCD brightness of about 200.
You also don't need "three pictures". That was a hack used for the oldest digital cameras that had about 8 bits of precision in their analog to digital converters (ADC). Even my previous camera had a 14-bit ADC and in practice could capture about 12.5 bits of dynamic range, which is plenty for HDR imaging.
Lightroom can now edit and export images in "true" HDR, basically the same as a modern HDR10 or Dolby Vision movie.
The problem is that the only way to share the exported HDR images is to convert them to a movie file format, and share them as a slide show.
There is no widely compatible still image format that can preserve 10-bit-per-channel colours, wide-gamut, and HDR metadata.
I wrote camera firmware. I’ve implemented HDR on the both the firmware level, and later at the higher client level when devices became faster. You’re either overloading terminology to the point where we are just talking past each other, or you’re very confused.
In the Apple Silicon era, the MacBook Pro has a 1,000 nit display, with peak brightness at 1,600 nits when displaying HDR content.
Affinity Studio [1] also supports editing and exporting "true" HDR images.
I have no way, in general, to share those photos with you, not without knowing ahead of time what software you’re using. I’ll also have to whip up a web server with custom HTML and a bunch of hacks to encode my images that will work for you but not my friends with Android phones or Linux PCs.