My understanding is that WebP is superior to Jpeg when encoding from a lossless image but: (1) if I upload a lossy jpeg what gains is FB really getting by usin

My understanding is that WebP is superior to Jpeg when encoding from a lossless image but: (1) if I upload a lossy jpeg what gains is FB really getting by using WebP? (2) Or am I taking a quality hit on what they serve? Let's say there's no quality hit and somehow they make a lossless WebP version of my lossy jpeg that still fits in 20% fewer bytes. Define X as the dollar savings gained by delivering these images scaled up to quadrillions of images served. My understanding is that WebP makes it's gains by a 10x longer encode. Define Y as the dollar cost of encoding and storing trillions of images in WebP. (3) What are the odds X is actually greater than Y?