A good icon should telegraph to the user as soon and as swiftly as possible the identification and purpose of the app/folder/thing it represents.

Photorealism is pretty good at that, since objects tend to look like themselves and nothing else, meaning they are unambiguous, and afford familiarity because even if your trash can at your desk looks nothing like the old photorealistic silver mesh trash can from Macs of yore, you can still probably figure out what it is really fast.

I am sick and tired of overwrought artsy fartsy mimmimulizsm hierogplyhic “icons” instead of something I can actually fucking see and recognize.