How is it more expensive (than Cloudinary, which the parent was talking about)?

Cloudinary uses a credit system and charges by disk space + bandwidth + transformation calls. Its free plan is metered and only good for up to a small number of monthly visitors.

Imgix charges by # of origin images, regardless of their size, and everything is included free. The free plan is up to 1000 source images and bandwidth/disk space are not charged (though fair use limits prob apply?)