The actual importance of having fun at work is less about the fun and more about building connections, but it IS part of the formula.
Fostering a work environment that brings out the best in people, involves engagement in many forms; challenges, recognition, shared goals, learning.... and definitely fun.
A team that has shared experiences and laughs together, is a team that will work harder for each other and be more apt to collaborate and push projects forward.
Additional parts of the engagement formula include:
+ Feedback loops
+ Connections w/colleagues
+ Trust in leadership
+ Value alignment