Currently, it seems that all of the images we upload are converted into lossy webp format, which means that the quality will always be reduced. If you truly insist on using webp, then I propose that, when uploading an image, users should be given the option to keep it in its original format unaltered, OR convert to webp. This will allow "generation loss" to be avoided, so that users can ensure image quality when they want it, while also allowing them to have the lossy webp if they are untroubled by such things.