I think you are ignoring a few things about web development. First, 16 workers don't equal 16 concurrent users if you have less then 16 cores in your server, i

I think you are ignoring a few things about web development. First, 16 workers don't equal 16 concurrent users if you have less then 16 cores in your server, if you don't then you still have a queue, it's just the queue the OS uses to handle context switches - which is even harder to reason about. Second, the entire idea behind event-based processing (what node.js and Java based netty or vert.x) as opposed to thread-based is that the bottleneck is rarely the cpu. Event-based processing is one of the ways to "avoid doing nothing".