The concept they use is “social harmony.”

This is a sort of shorthand for discouraging people from developing strong, dissident, aberrant or divisive political positions. Discouraging people from taking on political identities in general, other than a unified chinese identity. Discouraging people from disparaging and/or distrusting the government. Keeping fringey social trends out of the mainstream.

If you think of how strong political identities are currently in the US, this is exactly what they are trying to prevent. They want to keep everyone on the same page in terms of political and social norms.

The skeptical take is that the CCP is protecting itself from popular and democratic revolutionary movements.