is that because the West was actually correct or simply because the West won the cold war?

In Soviet Union many scientists knew that e.g. Lysenkoism was a fraud, they were just afraid to speak openly, because they would be fired or put in prison. When the threat was gone, the problem fixed itself.

Which is an evidence for West being actually correct. Hypothetically the scientists in the West could be operating under different threats... but then their mistakes would be exposed by current scientists in Russia or China.