A common use case for these high performance message passing libraries (not sure if that applies to the ones tested here) is in something like autonomous cars,

A common use case for these high performance message passing libraries (not sure if that applies to the ones tested here) is in something like autonomous cars, where you have many sensors and many systems interconnected through a bus, and ethernet comes in handy here. It's natural to broadcast grayscale images and larger stuff to the bus. If you have slow ass VMs passing data from Zurich to NYC, yeah, maybe don't send 1MB messages.