Re: Just got a Sony A7R4 and compared it to Nikon D500
From my experience Nikon and Canon (and Apple) have the best processing in camera of image data. Sony may have the best technical specs, resolution, autofocus, etc, but given RAW sensor data, Nikon & Canon make better images (in a 1/10 of a second) than I can tweaking in any RAW editor. My workflow is JPEG out of the camera (neutral or portrait picture control) into Perfectly Clear (90% go through w/ default settings, and the rest I tweak exposure a little or choose a different pre-set). I shoot RAW+JPEG so I have the RAW as a backup, but have never got better results from the RAW files.
With digital, ISO is less meaningful as a standard, it really should be gain. The Sony at ISO1000, exposes the same as the Nikon closer to ISO640, which may be expected with the relative pixel density of each sensor.
With the higher exposure of the sky, it looks like the Nikon just gave it all up to the noise reduction filter, as would our human brains (not much necessary detail there), and handled the buildings better. The Sony machine thought, "I've got 60M pixels to work with, there's detail to render here, how's this look?" and us humans went "ehh..."
Now, you've forced the Sony to work with the Nikon's settings, without letting the Sony work its advantages, newer lens and excellent in-body VR. I would venture to guess the new Sony lens is sharper when more open, and you can slow the shutter (2-3-stops beyond 1/focal length), letting you shoot at ISO 100-200. I doubt both cameras chose these exp settings in P-mode.
I'm a D500 diehard as much as anyone, and me with my D500 would probably outperform myself w/ a new A7R4. But given some time, I'd figure it out.