Users (including me) often forget to add attribution when uploading/linking an information. I'm not sure if it's 99% as this feature request claims, but it certainly happens less than half of the time.
When users upload images from their device, we don't know anything about the source of the image. (And if they made the image themselves, attribution isn't necessary.) But when they use a link, we do know the source. Just like the current uploader invites us to enter an image description, could it be modified in such a way that it adds a link to the original image too? Something like
[![enter image description here]] ([image source](https://example.com/image.jpg))
which would render as
The user can choose to expand it into a proper attribution (e.g. with the author's name) and even remove it if for whatever reason they don't want (or need to) provide attribution.
(unicorn picture taken from eastcoastvapor.com)