[msimpson]

Given this bloat resides in the metadata of PNG assets exported from Photoshop, couldn't this affect any operating system?

How many applications on Mac OS utilize PNG assets which were exported from Photoshop without any further optimization?

[0x0]

When you add a .png file to an xcode iOS project, it will add a build step to pngcrush the asset automatically. https://developer.apple.com/library/content/qa/qa1681/_index...

[msimpson]

Interesting. I did not know that. Would the same hold true outside iOS targets?

[saagarjha]

macOS supports true vector assets, so I'm guessing it reduces the need for such measures. But coming back to your question: I'm not sure, but both iOS and macOS use the same asset filetype, so I'd assume so.

[ghostly_s]

I would put good money on 'none'. Apple is way too much of a stickler about MacOS' graphics APIs to not be using custom authoring or optimization routines on assets. Edit: I presumed you're talking about first-party applications only, as you said 'operating system'.