I don’t know what a .webp file is but I don’t like it. They’re like a filthy prank version of the image/gif you’re looking for. They make you jump through all these hoops to find the original versions of the files that you can actually do anything with.
Edit: honestly I assumed it had something to do with Google protecting themselves from image piracy shit
I’d bet on WEBP simply because it was first out of the gate. Even though JXL is likely a better overall solution, it might arrive too late to dethrone WEBP. I’m already seeing WEBP in lots of places.