Looking back in February 1996, Chertok observed that the N1 would have been successful if Korolev had not died prematurely. Either he would not have allowed the first launch to proceed with unreliable engines; or he would have honestly analysed the reason for the failure and not allowed another launch until all the fixes had been made; or after two consecutive failures he would have stopped the trials and turned to Glushko to develop replacement engines. The N1 engines were finally developed into reliable units by 1974, hidden by Kuznetsov for 20 years, and then marketed to the west in the 1990's. The Kistler reusable launch vehicle would have used them, and there were plans to use them in an upgraded Soyuz launch vehicle, which would increase the payload to low earth orbit from 7 tonnes to 11 tonnes.
Glushko was responsible for convincing Keldysh, and then Ustinov, that the N1 could not successfully carry out the N1-L3M program in 1977-1980. Analysis in the 1990's show that he was incorrect, and the program would have been fully achievable. But Glushko wanted to start from scratch, with a new launch vehicle, new engines, and entirely new system. It took 13 years to develop those engines, and Buran proved useful only as a restaurant attraction in Moscow. The Energia was developed without any thought as to what enormous payload would require such a booster. There was a feverish search for a payload to justify it after it had been developed.