[JohnFen]

As a user, WebP doesn't really bring anything to me that matters. I mildly dislike it (not enough to really complain), though, because a lot of my tools still don't understand the format.

So, at least for me, it's 99% inertia.

[nicoloren]

Some browser or older versions don't support webp too. I think of the web browser in the Kobo e-readers for example.