Smartphone cameras have gotten better because of the DISP. The image quality like that on the Pixel 2 use an image processing chip like the Visual Core use techniques that perform processing on the raw image. The result is that it looks like it has been retouched and it takes less than a few seconds from the time the image was captured by the camera sensor to the time it is displayed on the OLED screen. The DISP allows more transparency for users providing auto-focus, auto-exposure and auto-white balance. That is why smartphone cameras don't really require any settings configuration, it's just point and shoot unlike with DSLR cameras which can be used in manual mode settings.
One technique DISP use is split channel processing. The chip captures the raw input from the camera's photodiode sensor (CMOS or CCD). There is no color initially, that is why a CFA is used to interpolate the colors RGB to the pixels in the final image creation. Prior to this the image is split into 3 channels RED to adjust contrast and gamma; GREEN to optimize details and BLUE to fix noise. Using the demosaicing algorithm, the final image is combined into a channel merge to produce the final output. Noise reduction and color correction are all taken care
