WordPress has long been planning on making webp the default image format. It has been a difficult decision with factors like negative community feedback, no support for webp in certain browsers etc, But last month, the decision was to go ahead with .webp as default and serve jpeg for non supporting browsers.
For now, WordPress won't be generating .webp out of jpeg image uploads by default for WordPress 6.1.
For those who don't know, .webp is an image format mentored by Google for creating low size, high quality images for web. webp format also supports animations like GIF.
A lot of browsers and platforms are still to adopt webp in its full power.