They didn't say that until it became clear to everyone that it was the case. The implication of this paper is that Fauci knew this all along. That there was no hope of stopping the spread with the vaccine. If that is the case, we were all lied to. Fauci has already admitted to other "Noble Lies".
Another implication is that the push to vaccinate uncompromised 5-year-olds was absolutely unnecessary and probably did more harm than good...ditto anyone else at low risk of serious disease.
I wish there were some method of getting to the truth to avoid these kinds of mistakes in the future. Unfortunately, a level-headed review of what happened will never occur.