alt Hacker Newsyou are right but at least in my experience it's very easy for a modern iPhone to capture a bad HDR photo, usually because there is some small strong highlight (often a form of specular reflection from a metallic object) that causes everything to be HDR while the photo content wouldn't need it
In beta testing this morning, the Halide “HDR slider” works as intended to solve that. Some of my photos have only needed +0.3 while a couple taken in near-total no-light-pollution darkness have it cranked all the way to max and that still isn’t enough.