Okay I'll bite - I have problems with this line of thinking. You're right that you'll never be able to cover 100% of all cases, but using that logic, your spec

Okay I'll bite - I have problems with this line of thinking. You're right that you'll never be able to cover 100% of all cases, but using that logic, your specs will never test 100% of scenarios, so you shouldn't write specs. I think the problem is you assumed it was "a magical box that people can rely to cover 100% of test cases of". That's a poor leap. It's clearly not. It's a good system to test a set of network failures at varying degrees. Just like any engineered system, it needs to be documented what it can and cannot do. I also eagerly await my do it all, 100% magic box.