Webp is pretty great actually. Supporting a 32bit alpha channel means I've actually managed to reduce file sizes of what were formerly PNGs by something like 80%, which drastically improved performance (and the size of my project). I don't get where the complaint of image quality came from either, as it seems to perform better than JPEG at the same file size.

The worst part is that you missed the real problem with the format: the CPU overhead (and therefore the energy cost) of handling the file. A high-traffic site can dramatically increase the energy required for the images processed by the thousands/millions of clients in a single day, which places a drain on the grid and emits more CO₂ (yes, this is really a thing that people measure now).

Basically Google invented the format to externalise their costs. Now, rather than footing the bill for bigger datacentres and greater bandwidth, they made everyone else pay for decompression.