To be fair, the stagnation is commonly said to have started with Brezhnev.
An interesting (but of course unverifiable) hypothesis is that Khrushchev's trajectory could have been different. Khrushchev supported OGAS (the Soviet would-be equivalent to ARPANET) and aimed to have cosmonauts on the moon by '67. Funding for the domestic intranet and space programs were later cut by Brezhnev. Khrushchev was also strongly anti-corruption and shook down the wasteful Soviet elite, which contributed to his ouster. A lot of the oil and gas fields that continue to power the Russian economy to this day were originally laid down under him as well. The "corn man" also greatly improved living standards, ended the gulags and purges, expanded the Soviet sphere of influence, loosened censorship etc.
Were the poverty, unemployment, and disillusionment worse than dying in a nuclear holocaust? Gorbachev spared both hemispheres that fear.
He also made it possible for Russians to read what they wanted, travel where they wanted, emigrate.
So, from the outside looking in, it looks like a mixed bag.
Anyways, Russians were miserable under the czars, miserable under communism, miserable with perestroika, and are miserable under Putin. Has Russia ever been a happy place?