English speakers have been deprived of a truly functional, second person plural pronoun since we let “ye” fade away a few hundred years ago.
“You” may address one person or a bunch, but it can be imprecise and unsatisfying. “You all”—as in “I’m talking to you all,” or “Hey, you all!”—sounds wordy and stilted. “You folks” or “you gang” both feel self-conscious. Several more economical micro-regional varieties (youz, yinz) exist, but they lack wide appeal.