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.
I’m not sure what point you’re trying to make.
Chromium and Android really are open-source. There are hundreds of products like Electron and Fire OS built on top of them without any involvement or consent from Google.
Just because Google Chrome and Pixel phones have some proprietary code doesn’t mean that Android and Chromium aren’t open.