I have asked for this very thing not very long ago. Instead of adapting to the WebP debacle and converting images to gif and whatnot, I have just found a very convenient way that only adds one extra mouseclick to saving the image from the browser to my pc in its original format. I say original because I have learned that the WebP format is being applied to all of these images (gif, png, jpg) by chrome as a means of image compression. The actual files are still stored online in their actual format so it's just a means of circumventing Chrome's default application of Webp format to all images.
If you are curious, I use INternet Download Manager as a download manager, and all I need to do is right-click whatever image I like, "Open image in new tab", and then right-click again in the new tab "Download with IDM". Works like a charm.