Google also might be at fault for making images on web lower quality. Several years ago, Google had announced that page load speed will affect the ranking. Google's tool, PageSpeed Insights gave recommendations on improving load speed. But it also recommended to lower quality of JPEG images to the level where artifacts would be visible. So instead of proper manual testing (using eyes, not a mathematical formula) on a large set of images, some Google employee simply wrote a recommended compression level out of their head and this forced web masters to worsen the quality of the images below any acceptable level.
So it doesn't matter if the photographer or illustrator worked hard to make a beautiful image, Google's robotic decision based on some lifeless mathematical formula crossed out their efforts.
Yes, this is made much worse by Google's "smartphone" crawler on pagespeed insights being an emulated very low end Moto G phone (10 years old?), downclocked to 25% of original (very slow) CPU speed, with a network that maxes out at 1mbit/sec or so, with 150ms latency added.
Makes it incredibly difficult to have nice imagery above the fold at least.
So it doesn't matter if the photographer or illustrator worked hard to make a beautiful image, Google's robotic decision based on some lifeless mathematical formula crossed out their efforts.