The design of the N1 was fundamentally flawed, especially for the time. The huge clusters of engines were simply not viable.
Even with 5 F-1 engines, the Saturn V had tens of thousands of separate parts. The N1 had 6x the number of engines, built on the cheap with a very sketchy labor force.
A huge number of things were bound to go wrong, on every single stage with clustered engines (the first 3 IIRC).
Especially with the extremely spotty safety record of early Soviet designs, and how late they conducted their "testing" (relative to the Apollo program), the N1 never could've realistically gone anywhere (safely, that is).