>>191567891. Use a Chromium addon called "Header Editor"
2. Set a global rule that removes WebP from the accept header for all requests. Not a single WebP image will be served to your browser after that.
Extension:
https://chromewebstore.google.com/detail/header-editor/eningockdidmgiojffjmkdblpjocbhghI can't type in the rule code here because content sanitization by 4chinz. See picrel instead.