Your observation tracks with my experience with the camera as well, but only when in Auto mode. I've not seen this mentioned in any reviews, but in my personal testing there is a HUGE difference between the quality of the Auto camera mode and the Manual camera mode. Photos taken in Auto are blurry messes, while Manual photos are much crisper with lots of retained detail. I have no idea what LG was thinking when they clearly chose to smear the images in Auto mode like that.
Manual photos compare well to the Google Camera app in terms of detail, but I do usually prefer the look of the images that come out of the Google app better.
So my personal workflow is to use the hacked Google Camera app for most stills, switching to the LG app if I need a very low shutter speed or some other tweak. I use the LG camera app for video and always use it in manual mode for the versatility it provides.