What good is Congress if they didn't stop Steve Bannon from making truth a thing of the past that only communists long for?

The goal is not to prosecute him but to force him to obey the subpoena like any other citizen and hopefully tell the truth. Although he undoubtedly will take the Fifth Amendment of the Constitution when it becomes clear that Trump's Executive Privilege claims are not valid. The one thing everyone knows about the Constitution: the Fifth Amendment.

Yes. The best way to fight pretending is with more pretending.