[Cyph0n]

Well, that's not really the case with higher-scale router operating systems like IOS-XR. You have a ton of protocols running in software, so performance and memory requirements increase quite a bit.

And then there are the high-availability (HA) requirements which typically lead to redundancy in software and hardware.

[turtlecrush1337]

Quite right. Control plane traffic is punted to the CPU, and a Raspi CPU cannot really handle that volume of traffic at enterprise scale.