They certainly are. But my point is that if you're only servicing the same number of IO connections as you have cores, it's not extremely scalable.

Most networking servers should be dealing with hundreds or thousands of concurrent connections.

The linked article didn't make this clear, but this feature is mainly designed for process-per-core models, not process-per-connection. The problem you run into with most existing process-per-core systems is that you can't ensure an even distribution of load across the processes without introducing extra overhead. SO_REUSEPORT offers some convenience when changing the number of processes, but the real benefit is that in this mode the kernel uses a better load-balancing scheme.