Why is Jean portrayed as a social climber in Miss Julie?

In August Strindberg's play Miss Julie, Jean is portrayed as an opportunistic social climber because he represents the rising class that is poised to overtake the declining aristocracy.

While Julie is depicted as a member of an aristocratic order whose era has passed, Jean is characterized by his ambition and his ability to navigate the social and psychological factors of his time. Strindberg frames Jean as a figure to whom the future beckons, contrasting his upward mobility with Julie’s inevitable social and personal decline.1