Straight from the horse's mouth! The thing is that Brotli is clearly optimized for the web (it even has a built-in dictionary), and ZStandard is more generic,

Straight from the horse's mouth! The thing is that Brotli is clearly optimized for the web (it even has a built-in dictionary), and ZStandard is more generic, being used for tar archives and the likes, I wonder how PDF would fit in here.