I absolutely can compare them. For example, if you work full time, and sign up for too many classes, your grades will suffer as you don't have adequate time to devote to them.
If you have a family, and have to work less or have less time to devote to work, your employment will suffer and you will miss opportunities to move up the ladder.
Time investment, effort, and reward are closely related in all aspects of life. Multiplayer games with competeition are no exception.