I think there is some confusion here between shutter speed and the time it takes to take a picture.
I agree that in auto mode the camera favours a slow shutter speed over fast iso, which is frustrating when taking pictures of people or capturing fast action. However, manual mode remedies this.
As for the time it takes to take a picture, this varies depending on a few factors - the shutter speed selected and the focusing time. In good light the camera will focus quickly and have a fast shutter speed, so pictures will be taken almost instantly.
In low light where the camera may struggle to focus quickly, it may be better to use manual focus.
Alternatively in these situations you can shoot in 4k and extract 8mp stills from the footage later. A great feature of this phone is manual video mode, so you can select the shutter speed in advance. I find that shooting at around 1/125 shutter speed is enough to be able to extract crisp stills of slow moving objects from the 4k footage.