To avoid fighting! Ryan (the middle boy) was getting jealous that Josh wasn't buckled and was sitting on a soft seat. And it was becoming a whole *thing*. So! We got 2 Yepp seats and the problem was solved! Feels even safer to have them both buckled anyway. Josh (5 years old) I totally trust to be on a soft seat. But! Ryan is 3 and still might fall asleep on longer rides after a long day at school. I love knowing he is strapped in and safe just in case.