No optimization for png images?

And the original from DA is 17.9 MB
 
Look at the image, there’s a grain effect applied to it for that early 90s VHS look; stuff like that bloats PNGs, a lot, and there’s nothing lossless compression can do about it.

Indeed - we do actually perform optimization for PNG, but if people intentionally add pure entropy to their images we can’t optimize that away in PNG, we’d have to render it in a lossy format.