I'm starting to use my iPhone 15 Plus with Lightrooms' camera and HDR. HDR looks great on the phone and in a laptop (MBP M1) but the web versions are very disappointing. All of which makes me wonder what the point of using HDR is. Unless a viewer has HDR compatible hardware, you are left with gorgeous pictures for yourself but not for others. Is photography really meant to be a narcissistic activity? : )
I am not too sure what you are getting at here.
HDR is a method of handling very high dynamic range scenes where you want to retain detail in both very bright areas and very dark areas. Typically when taking a single image you have to choose between detail in the highlights but none in the shadows or vice versa.
However, if you take multiple images at different exposures, you can merge them together to get a single image that has both details in the highlights and in the shadows. Phones do this more or less automatically. With a camera you can either output all the image files and merge them together in post processing or you can do it in camera and get a single merged jpeg. Many cameras will do both - output both a merged jpeg and the individual images. Merging in post processing from multiple raw images will give you the best possible output quality. It will also enable you to produce deliberately unnatural looking images if you want to - this was all the rage 10 or so years ago.
HDR works best with images with no movement in them. Fast moving objects in the image are liable to show motion blur to some extent depending on how good the merge software is.
It sounds as if you are picking up one of the individual images from your phone when you try to post to the web. That is a workflow problem.