My theory:
Looks actually like a Bad Quality photo, does not mean it's a bad photo. Looks like it's taken with a phone or a digital camera with software zoom not optical zoom. It can be through a glass that it's not that clear or even a not-good/blurry lens, the reflection in the water it's pretty realistic, does not mean that painters aren't capable or replicating this water realism but it looks pretty photo-ish to me.
It's blurry especially on the borders, and not sharp at all. It's not that grainy because there's plenty of light, but we can see noise in the overall photo in the colors and the light of the picture. I downloaded the picture and ran it through affinity photo with noise reduction in color and luminance, and sharpened a litte, this way looks more like a bad quality-filtery-photo.
I'm not sure. Maybe your version looks even more like a good painting. It would take quite a lot of skill to paint that.
Maybe, i agree. Actually i follow a few amazing realism painters that make me cuestion the photo. But my theory comes from some test i made with DSLR and phone cameras, and i found it more leaned to a bad quality photo. But again, yes, that's why it's just a theory.