This is a really old type of propaganda. Sergei Eisenstein wrote about it, after he visited France in the 1920s:

“Why aren’t there any comedies in your country? Is it true the Soviets have killed laughter?” A deadly silence ensued. Usually I am slow at finding a proper answer, especially in front of the public. But this time I had a brain-wave. Instead of replying, I burst out laughing. “They’ll roar with laughter in the Soviet Union when I tell them of your question!”

Good article, though it’s a bit unfair to call Brezhnev “frail and confused” when he won the trust of the nomenklatura: he was quite young really. He held power for 18 years and when he died he was still younger than Biden is now.