To my knowledge, not even every Google product supports it, but I have not verified support myself.
I blame Google for pushing it, but I also blame every third-party product for not supporting it, when it is mostly free to do so (I'm sure all of them internally use libraries to decode images instead of rolling their own code).
I think it works better in a totally open source ecosystem. I can share webp pics to my daughters via xmpp for example regardless if I am on my smartphone (conversations) or desktop (gajim)
I blame Google for pushing it, but I also blame every third-party product for not supporting it, when it is mostly free to do so (I'm sure all of them internally use libraries to decode images instead of rolling their own code).