In this case each request is very tiny amount of work on the client, so waking up a thread to do that work just to immediately block waiting on the response fro

In this case each request is very tiny amount of work on the client, so waking up a thread to do that work just to immediately block waiting on the response from the server is very wasteful. With async you can send hundreds of requests in a simple loop, on a single thread. It's not only more efficient but also actually easier to write.