I too agree that the Pixel is one of the best cameras on the market and *the* best, IMO, if you are strictly limiting your search to Android devices.
My Google Pixel 2's photos rival my S10 ones - not that my S10 takes bad photos, though, it's just that I find that Pixel phones do well with things like moving subjects. My cat is my constant photographing subject and sometimes my S10 has trouble keeping up with the movement.
Let us know what you decide! Also, check out the "Pixel 4 Photos" thread here at Android Central to see some really neat pictures!
Moving subjects (my dog and grandbabies) are the bulk of my photos as well. I've just about decided to go with the iPhone, as much as it pains me. Their camera and video quality make it hard to not jump ship.