… the Catholic Church does not maintain, and never has, that the bishops and the pope are “other apostles” in the strict sense of the word. She teaches something quite different, that they are “successors of the apostles”. What does this mean?
There is not for one moment any question, nor has there ever been, that the bishops or even the pope may build anything at all on any foundation other than that laid by the apostles. They not in any way assume the role of new founders, more or less independent of the first. Their role is to preserve and transmit what was communicated directly by the apostles. The faith of the Catholic Church is not something different from the faith of the apostles. The Word proclaimed by the bishops is exactly that which the apostles were the first to teach.
Louis Bouyer, The Word, Church and Sacraments in Protestantism and Catholicism, 52.