In the context of the song, "paying dues" can be interpreted as experiencing setbacks, overcoming obstacles, and facing adversity along the journey to success. It implies that the champions have endured and persevered through these challenges, which has ultimately led them to their victories and accomplishments.
The phrase "you have paid your dues" is often used in a broader sense to refer to any situation where someone has worked hard and diligently to achieve their goals. It acknowledges the sacrifices, efforts, and commitment that individuals have made to reach success, regardless of the specific field or endeavor they are involved in.