I know, I work in digital image processing, and I'm an amateur astrophotographer. Demosaicing is not on the same level as star registration, stacking (posibly HDR processing in the middle), plus some more AI driven "magic" in between.
That's what I'm referring to: for the shown image "without post-processing" the phone has performed a lot more actions after demosaicing, that's why i say it was heaviliy processed.