In more general terms, state torture has nothing to do with intelligence gathering, even as that is the insisted goal. And as previously mentioned, it does create compliance in the subject, but even that is not the real goal.
The real, ultimate goal of any kind of institutionalized torture is to change the character of the the institution and the state that inflicts it. To make torture socially acceptable, to even make it desireable. The US is already half way to the point where such niceities as "due process" and the old conventions of constitutional law are tossed away for feel good (read feed the blood lust of the mob) instant solutions.
This is all part of the same process that has vilified the judicial system, intellectuals, and progressives, in favor of hollow patriotism and mindless lynch mob populism covering the Right's authoritarian brute state goals.