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
Paint.net is one of the first apps I install on every new computer. It’s just excellent for quick and dirty image manipulations.