One problem is, the lens could/will affect the image as much or more than the camera itself.
I put a pro grade 70-200 lens on my D7200, and the images were like from another camera. It was sooo much better, compared to the standard 18-140 lens. I did not have to upgrade the camera, I needed to upgrade the lens, to get the most out of the camera.
Another is that you cannot see the effect of HIGH rez/MP unless you crop deep into the image.
I think this question can be rephrased as: "What's the best camera?" The problem you'll run into is when comparing two cameras capturing the same scene... one will produce an image more to your liking. For that scene.
For all the others, it may or may not. In other words, a camera with a max ISO of 6400 may be perfectly fine for landscapes, but when you really need higher ISOs for sporting events or BIFs, your 'ideal' camera will fail miserably. Also, the settings used in the cameras will most likely not be the ones you would have used.
So what is the best camera? There is no one answer. If there truly was ONE 'best' camera, it would be the only one on the market and the question would be moot.
What's the best camera for you? You need to do your own research. Yes, reading reviews and on-line comparisons is fine. But you need to figure out what features you will need in your camera in order to achieve the results you want. Find which makes and models have those features, then go hands-on with them to see which ones work best in your hands. Model A may have all the bells and whistles you need, but if setting it up the way you need it to be is clunky and time-consuming, look at Model B. If Model B makes it easy to work, then there's your best camera.