processFolders webp version ~ 10x bigger than jpg versions

[zwergius]

Hey,

So first of all a big thanks for all the effort which has gone into this, I used to use the Gatsby version myself and quickly came to think it was invaluable, so very happy when I found this for svelte/sapper!

I am using processFolders to optimise my images. But when using this option I seem to get webp versions that are more or less 10x bigger than their jpg counterparts.

Webp versions in big sizes is also even bigger than originals.

I am running latest versions of Sapper, rollup et al.

This is my relevant rollup config: