This is the correct answer. Lap belts are there because under unexpected conditions planes can and have[1] suddenly hit turbulence pockets where they plummet 10 or so meters in an instant. The effect is anyone unbuckled gets slammed into the ceiling.
It's why if you're seated, it's recommended to be buckled in - the difference between one person slamming into the ceiling and 300 is pretty substantial.
It's why if you're seated, it's recommended to be buckled in - the difference between one person slamming into the ceiling and 300 is pretty substantial.
[1] https://abcnews.go.com/Health/story?id=7391144&page=1