yeah, atrocious: I can reach roughly 20Gbps routed on my not too expensive home Opnsense box with firewalling and many other features (which is absolutley unnecessary for me). No routing by a CPU is not for routing between Comcast and Google, but it has it´s place and works so well, that a lot of opensource routing projects were supported by big vendors and telcos. Also networking for containers depends on this...
Just the software doing the routing is not running on your main CPU, but on the CPU bundled on the board.