When there is high-contention for a resource, it's better that one thread do it and access it contention-free, rather than make multiple threads content for it.

Even so-called "lock-free" synchronization has locks, they are just very short (30 clock cycles). Therefore, you still want to avoid contention if you can figure out a way to do it.

I didn't really go into enough detail in my example, but pulling packets off the network is a good example. You can have one thread do it, and therefore need no contention. Then you can setup multiple single-producer/single-consumer ring-buffers to forward those packets to worker threads to complete the processing of the packet. Thus, you essentially get rid of all the atomic/lock-free contention you would otherwise have.