[cooker] What about mozjpeg?

Hi,

as you may remember in 2015 we switch to mozjpeg as default JPEG encoder.
According to this libjpeg-turbo | About / What About mozjpeg? a mozjpeg is
slightly better at compression, but tremendously slow compared to
libjpeg-turbo. I have feeling that even if our mozjpeg is compiled with PGO
it is still inferior to libjpeg-turbo.

There are not much data about benefits of mozjpeg these days, as i doubt
that better compression is something that typical user pursues for.

Can we start discussion to move back to libjpeg-turbo as default JPEG
encoder ?