It's just the first real event of a movie to happen since COVID. Huge, vibrant production targeted at the 20-30 age group. It also popped up fairly organically. There have been memes of people getting dressed up to go to the movies like minions, but Barbie was the first movie where I saw it pop up through people excited through the movie. It's not a perfect movie, but it's a social event the likes we haven't seen in 3-4 years so people are going crazy.