Yes, it is better to do postgraduate education than to immediately get a job after graduate education is finished. The higher a person's education is, the more likely it is that this person will contribute to society on a grander scale. Just think of all the doctors society would not have if they had stopped at the graduate level.
In the current economic crises, more and more students are deciding to continue their education to masters or even Phd level. But is this always such a good thing? Are their career prospects better enhanced by another few years of study or not? Yes, if there are jobs available, but on the other hand, entering at a higher level means you become more specialized and make you less pliable to employers.