What are some ways a CSR benefits from contributing to team work efforts?

Customer service means interacting with customers, and any effort put into the team's work will pay off with happier customers. A CSR who has happy customer's is going to work better, enjoy the work more, and be part of a team.
Customer service is often viewed as a somewhat passive work function; taking phone calls, or handling routine customer interactions like retail point-of-service sales. But the CSR position is active, and with excellent, consistent customer service the company benefits in many ways, large and small.
Customer retention, new customers, and employee retention are just a few of the ways superior CSR training and practice make a difference to a company. The teams that research, develop, and maintain product lines or services need the CSR but they may not realize it if the CSR remains cut off from that team.
In summary, a CSR benefits from team membership and inclusion through (1) better product or service knowledge and expertise; (2) integration into the company's overall mission; (3) better likelihood of integrated supervision; and (4) opportunity to provide feedback to the team about customer satisfaction.
In terms of the CSR and their own team (other CSRs) the feedback loop of happy customers is the main benefit. If the CSR can't handle a customer, or is absent, and that customer has a rotten experience with another CSR, the original CSR is going to experience that negativity. A secondary benefit for CSRs who contribute to CSR team efforts is cross-training, giving CSRs who are contributing an advantage in terms of job function skills and product/service knowledge.