Not sure how common this practice is, but some manufactures (like TP-Link) include a function that they refer to as Hardware NAT - and like the name suggests it acts like a hardware accelerator for performing LAN <=> WAN routing, and as long as you don't require any complex configuration (since you are only moving package back and forward between the LAN and Internet) this works fine and it's perfectly capable of reaching 1Gbps on very cheap equipment, since the CPU is no longer in play.
Most consumers never bother with anything else, since they also have no interest in any advance routing configuration, and they do get the full 1Gbps that they pay for.
Anonymous