Pushing the nuclear family as the exclusive option. This displaced multi-generational living & chosen family that sociologists tell us were the norm in the past, and that continue to be common in other cultures.
The consensus among sociologists is that the nuclear family wasn't the most common option historically, and isn't the most common outside of the West: [1][2][3]
The decline in construction and use of porches, due to widespread adoption of air conditioning.
Nazi Germany
The government-backed German Labour Front was created to replace the independent labor unions that the SA had destroyed. The government then outlawed collective bargaining and striking.