I looked at the images now and I will tell you for a fact that they are not being transcoded and saved. to transcode and save image to desired format you have to have set the following environment variable for the pictrs service in the docker-compose file: PICTRS__MEDIA__FORMAT=<your-format>

When I look at your communities, I find images saved as png, jpeg, jpg, but not as webp. Saving images as webp/avif/jxl will result in an incredible reduction of storage requirements.