[xenonite]

This is only one half of the story. Given the increased network bandwidth, decoding speed matters. And here, JPEG is much faster. Also note that the JPEG decompression algorithms are highly optimized and coded in assembly language, and there are maybe even hardware decoders.

On android:

WebP 66% less file size than JPG, 267% more time to decode.

WebP 38% less file size than JPG, 258% more time to decode.

WebP 89% less file size than JPG, 319% more time to decode.

https://stackoverflow.com/questions/37812950/jpg-vs-webp-per...

[baybal2]

On Android, JPG decoder lib may or may not use a DSP on Qualcomm SoCs, WebP doesn't have any hardware decoding support.

Any size gains will be much more noticeable in the context of network transmission.

[chrisandchris]

Which comes back to people having good phones most probably will have better internet and people habing cheap phones will have less good internet.

So you‘ll lose time either on transfer or decoding.