Ah, in that case you would be more annoyed to learn that lossy WebP and lossless WebP are completely distinct. They only share the container format and their type codes are different.
Awesome. It would be interesting to learn why they even thought it is a good idea. Content-agnostic containers may make sense for video, but for the vast majority of use-cases a "video" is in fact a complex bundle of (several) video, audio, metadata tracks, so the "container" does much heavier lifting than specifying codec details and some metadata.