If the objective function was a separable function of the different parameters you could simultaneously optimize over them with ease, but that's obviously not t

If the objective function was a separable function of the different parameters you could simultaneously optimize over them with ease, but that's obviously not the case very often in life. In general optimizing multiple objectives (or one objective subject to additional constraints) would achieve a compromise between them. If you are trying to simultaneously maximize equality of opportunity and equality of outcome you would just achieve a trade-off where neither side is happy. On the other hand if you were starting out just trying to optimize for profit, then adding a constraint or additional objective will just mean you make less profit in achieving that other objective. I suppose that could be called more fair if you're trading off profit for fairness.