I make plenty use of async requests to get files (images) and make web service calls at the same time. It's a Xamarin mobile application. Mobile apps are sometimes constrained by latency, so having a few requests in flight at once speeds things up.
Performance is not just fewer CPU cycles.
> IIS has many threads available to it, that's my entire point
My web services run on a VM with four cores. That's what I get given, and there's another twenty websites on it. The less overhead my code has the better. Just because it's not 100K TPS doesn't mean there aren't benefits.
So why bring it up?
And as for your condescending "Blocking operations ... block", talk about missing my entire point.
IIS is the victorian sewer, your code is the hose. IIS has many threads available to it, that's my entire point. You don't need async/await to free up those threads, it's got a ton of them ready to go.
Most programmers are not going to hit the thread limit, and when they do they can upgrade hardware while they figure out the tiny few high-impact async/awaits that would actually mitigate the problem.
It's pointless pre-optimization. We all talk about how evil it is, so why is it suddenly not evil with async/await?