When exporting a PDF, there are several options to compress images: JPEG, JPEG 2000, ZIP. And we can choose the image quality, from Min to Max. To a degree, PDF file sizes can be reduced with these settings, but at a certain point the image quality is too poor for anything meaningful. WebP has incredibly high quality for a low file size, plus it supports an alpha channel.

This feature would automatically benefit Photoshop and InDesign as well, as they share these presets.