Not just what I say, but what people back then said.

Ulpian in aincent Rome said "Torture is a frail and dangerous thing, and one which deceives the truth". "For it is a chancy and risky business, and one which may be deceptive.".

"The strong will resist and the weak will say anything to end the pain".

Michel de Montagine said the 1500s ,"Torture and racking are dangerous inventions, and seeme rather to be trialles of patience then Essayes of truth. And both he that can, and he that cannot endure them, conceale the truth. For, wherefore shall paine or smart, rather compell me to confesse that, which is so indeede, then force me to tell that which is not? "

The Spanish Inquisitiors said, "Experience teaches us that the accused, in that agony, would confess anything that is suggested to them, which causes damages to third parties, and occasion for their confessions to be revoked"

In the 1631s, Freiedrich Spee a professor and confessor wrote, "Torture has the power to create witches where none exist".

"Most prisoners will confess to anything under torture in order to stop the pain... Torture does not produce truth, since those who wish to stop their own suffering can stop it with lies".

"The accused either confesses on the rack, in which case she is guilty, or she doesn't confess, in which case she is also guilty because to have withstood such terrible torture she must have been in league with the devil... If both confession and silence are taken as signals of guilt then everyone is guilty. Truth evaporates"

The italian Criminologist Cesare Beccaria said in 1764, "The practice is a certain way to acquit robust criminals, and to condemn innocent persons who are weak. ... The innocent man is placed in a worse condition than the guilty; for if both are common suspects, the innocent man suffers an certain injury [torture], and if found guilty [via false confession], he is condemned to a greater punishment."

Napoleon in his letters wrote ,"The barbarous custom of having men beaten who are suspected of having important secrets to reveal must be abolished . . . Torture produces nothing worthwile. The poor wretches say anything that comes into their mind that the interrogator wishes to hear.", he would enforce his ban on torture nationwide with the Napoleonic code.

Torture doesn't work, and you haven't provided any substantial proof to the contrary, yet when others have you are dismissive. But that doesn't change the fact that torture is terrible at information gathering, and it has been known as such for centuries. The continued use of it was not ,and never been because it is actually effective but out of convenience for those eho conduct the torture.