The problem is that in the abstract 4 years is meaningless. 4 years of what degree of sacrifice? For what pay off? At what stage in your life? These details are vital for people to make a decision.
Delayed gratification is essential for most grown ups. But some people (women in particular) can delay that gratification too far and never get it.
Most degrees are 3 or 4 years in the hopes of a better paid job at the end. Internships are exploitative sacrifice in the hopes of well paid in the end.
Many women step out of the work force for a bit. Sacrificing earnings for 5 or 10 years for the pay off of a different sort of relationship with their children.
4 years unhappiness/sacrifice when you near the end of your life is usually not worth it. But even then some palliative chemo etc can be a 'sacrifice' in order to gain extra time.
So details are vital. Not just because we hate goady drip feeding