According to the communists, why was it important to destroy the "4 Olds" during the cultural revolution

Before answering, let us first establish what these "4 Olds" are. The "4 Olds" that we are talking about here are China's Old Ideas, Old Customs, Old Culture, and Old Habits. Mao Zhe Dong, the founding father of the People's Republic of China, was the one that led into the annihilating of the "4 Olds" of China. This is in response to what was currently happening at that time. There was a Russian revolution which began failing and became one of the reasons that led to the destroying of the "4 Olds". Urban Stratification was also feared to come up. And this way, elitism would be demolished. Some would say that Mao wanted to secure his own place in history which pushed the decision on destorying the "4 Olds".