Libraries that need to scale out faster than other ones tend to be CPU intensive (or RAM intensive, which tends to imply CPU intensive since you will be missing the cache a lot). Those sorts of tasks are rarely bound by network traffic, particularly when you are within a single data center, where latency is low and bandwidth is free.
Are there cases where you need to scale one library possible without the network (IO and latency) becoming the bottleneck? The way most microservices get used as RPC mechanisms you hit the network bottleneck very quickly.