I’ve been running the new Kirby 3.6 alpha for a few versions now and my favorite new feature is the support for AVIF and WEBP image generation. I’m a sucker for better web performance and finally finished my small improvement to the image block. This version of the image block outputs a picture element with an AVIF, WEBP and the original format image. The width and quality parameters are currently hard-coded at 1200px and 60%/55%, respectively, which works well for me so far. Mileage might vary.
For a future iteration I want to add a field for image width and quality, but for now this simple version will do.
Find the code in this Gist.