First being the most obvious, a team sport can encourage children to be more outgoing and inclusive with their peers.
Being in an environment where good-sportsmanship and fairness is constantly pushed upon you definitely has a positive impact on social skills and fairness with others.
Team sports can also teach healthy independence and contribution in teamwork—
Yes, later on in life the child could finish an entire group project by themself and none of their peers would have to lift a finger. However, with every other person’s creative output and individual thought process being pushed out the window, this often creates a one-dimensional piece that could be missing out on ideas that would boost the finishing product substantially.
Point being, team sports teach children the importance of contribution and unique-to-self capabilities. Whether it be in the classroom or at home.