After torture "worked" why did it take so long to then find and kill osama?

“The bottom line is this: If we had some kind of smoking-gun intelligence from waterboarding in 2003, we would have taken out Osama bin Laden in 2003,” said Tommy Vietor, spokesman for the National Security Council. “It took years of collection and analysis from many different sources to develop the case that enabled us to identify this compound, and reach a judgment that Bin Laden was likely to be living there.”