But why? Why would I do that?

Especially as literally no one ever looks at that on lemmy, and a fraction of the fraction of people who save the images do it.

Not to mention the poor survivability of such metadata when hosted, federated, proxied, thumbnailed, or worse, screenshotted.

If you want neatly organized files, I suggest writing a danbooru ripping script yourself.

Why would I bother to do that for you? As you're essentially the sole case that would benefit.