Great idea. Lossless WebP is generally a superior alternative to Png (except it cannot handle HQs beyond 16k on a side), but when you get served a webp on a web site, there is a 95% chance it is just a Jpg that has gone through another round of lossy compression, a different type, at a lower bit rate = worse quality (fewer fine details).

In an ideal world, the digital master would be encoded as both Jpg/Png and Jxl, and the browser would have an option built in to preference one format over the other. JpegXl is the best new format. Jpeg2000 was decent but I don't think any browsers support it, and it even has a lossless format.

Unfortunately, this extension only works on some sites. Some are still sending me Webp,oravif (less often) and even twice I got a Jpegxl (I wish to force jpeg from these bossy CDNs that are enforcing inferior formats upon me).