I think young people might complain more because they usually have less patience and higher expectations. They are used to a fast world where they get things quickly, so if something isn't as fast or smooth as they want, they tend to show their unhappiness. For example, I've seen my younger coworkers quickly criticize low efficiency at work, which comes from their high standards and wanting things to move fast.
若者は、普通に我慢強さが少なく、期待が高いため、より多く不満を言うかもしれません。