The term 大家 (dàjiā) is a window into the collectivist nature of Chinese culture. While in the West, the individual is often the primary social unit, in China, the group (the family, the company, the nation) holds immense importance.
Group Harmony vs. Individualism: Using 大家 subtly reinforces the idea of the group's precedence. When a leader says, “希望大家努力工作” (xīwàng dàjiā nǔlì gōngzuò - “I hope everyone works hard”), the focus is on the collective effort for a shared goal, rather than on individual performance.
Comparison to “You All” / “Everyone”: In English, “everyone” or “you guys” is a simple plural. It's a summation of individuals. 大家, with its “big family” origin, has a warmer, more unified connotation. It's conceptually closer to the inclusive, friendly feel of “y'all” from the American South, but with a deeper cultural foundation in group identity. It dissolves the speaker/audience barrier, often including the speaker themself within the group.
Using 大家 shows cultural awareness by acknowledging and respecting the group as a single, important entity.