Not that many people were unhappy. The following video was filmed by someone like you who hates the USSR. A young Russian liberal, who's angry with Putin for not flying rainbow flags over the Kremlin. He asked people on the streets of Moscow what they think about the USSR:
Here is a similar video..
It wasn't as bad as it is portrayed by the Western cold war propaganda that you apparently have swallowed, hook, line, and sinker. You're claiming there were slums or that Eastern Germany and the USSR were dumps. Actually no they weren't. People took care of their communities, their streets. You didn't have the criminality, drugs, homelessness that is seen in capitalist-run countries.
All of that however is irrelevant. I'm not a Russian Bolshevic communist, or Chinese communist, or even a Cuban communist despite my parents being Cuban. I'm an American communist living in the 21st century, so your insistence on equating all communists and their communism to conditions of the last century is naive and disengenious. We have a lot more technology today, hence communism would function a lot better than it did in the past. More, if America converts to communism, it won't have to deal with a capitalist empire as it once was, threatening socialist countries with war and imposing economic sanctions. All of that will end if America converts to communism. America would have it easy.
You keep ignoring my question. How will capitalism solve the quandary of advanced 21st-century automation technology replacing wage labor? Once and for all, answer the question.