Comment by M-Valentino

My idea for wanting PNG encoding is that they have lossless compression, and that the other common format that preserves details is bitmap, which has no lossless compression. At least PNG might compress photos somewhat. The web is plagued with images that have been resaved over and over that have JPEG degradation. I did not know JPG-XL had a lossless format so that's promising imo. But JPG-XL isn't supported in many browsers.