Communist China is a country of slogans. I guess that chanting slogans is a way of educating a country whose population is dominated by illiterate people, so the slogan strategy was a creative idea. There’s a lot to say about Mao Zedong, but the guy understood his base.
Slogans haven’t gone away. The government uses them everywhere to promote civil virtues. The train station in Shenyang displays these slogans: