The burden of protecting Pete's records rested on Roddick, Hewitt, Safin, primarily on Roddick and they all failed magnificently. By the time Nadal peaked it was already too late, Nadal did enough dents on Roger but that was too late. Roger was already on 12 slams when Nadal became world number 1, only a matter of time from that point.
On the other hand, the burden of stopping Nole, rested on Federer, Nadal, Thiem, Murray, Stan, Medvedev, Tsitsipas, Alcaraz etc etc .... many people, collectively they all failed but for a good reason, credit to Djoker.