If only this image was also .webp, that would be the cherry on the sunday
webp is a completely open and free standard. So is AVIF. I don’t blame any web site for using webp. It’s just better. It saves them money on the bandwidth bill and makes their web page load faster.
I blame all the other apps for not supporting it properly. It’s been well over a decade since these formats came out, and the major browsers have supported them for at least 5 years. There are numerous free libraries for them. Any app you want to use images with should just work with them as easily as a jpg, gif, or png. There is no excuse.
This is a webp sample image. I dragged it to my desktop from Firefox. Windows showed the thumbnail properly. I dragged it into this forum. Oh, look, there it is. You wouldn’t know it wasn’t a jpg, because Firefox, Windows, and Discourse are all properly updated software.
TL;DR: If you try to use a webp and it doesn’t work, get angry at the software it doesn’t work with, not at the web site using a webp.