@cdevroe LOL! I don't have an opinion on the format either and I do know that many webmasters upload way over bloated images for display on the web. They just don't know any better. But if I upload a .jpg or a .gif file to my hosted, paid Wordpress instance, I expect it to stay a .jpg or a .gif. I don't expect it to be changed into a different format without a by-your-leave. I consider that a hostile act. Unless WordPress is going to start paying my hosting fees.
That said, on WordPress.com it might make sense.
A lot will depend on the UI. If we can just check a box that says No WebP(oo) images and forget it then it might be okay.