Not being the bottleneck doesn’t make increased throughput completely superfluous. The faster you can communicate across a channel, the quicker you can shut up

Not being the bottleneck doesn’t make increased throughput completely superfluous. The faster you can communicate across a channel, the quicker you can shut up and get to idle, saving power on both transmission and policing of resource contention. You also have more time to handle locally scoped retries and error correction.