I would say it depends on a degree you are getting, of course. For if you are dreaming of a business or IT career and spend your time in learning English Literature, the hesitations that make you ask those questions are quite logical.
Still, if you are one of those lucky people who study the subject of their passion and dream of working in the same sphere, then probably your studies are quite useful for your future career. Sure, they lack a practical experience you can gain only while working, but they probably will give you much more than that. You’ll have all your adult life for gaining that desired experience. So, while your studies for getting a degree still on, I would recommend you to find positive sides in learning (if you still haven’t found them).
What kind of skills would you need in future, when making a career? Apart from practical skills related to your job directly, of course.
As for me, the graduate degree itself won’t make you achieve your career goals, but it can serve as a compelling basis to form out a character, which eventually will bring you on the top of the world. But only if you will work hard on it.
Getting a degree can abet your self-discipline (how else on earth is it possible to meet all the deadlines for the assignments and exams), teach you how to find the way out from a terrible situation (like when you have no idea what is that exam all about). It also can teach you a handy skill which is the ability to analyze a lot of information in a short time and make the correct conclusions. You should know the fact: 90% of all the information humanity knows nowadays appeared in last 10-15 years. This process won’t stop. And those who are skilled in recognizing real facts, define what is right and wrong about the presented information, who can do it quickly and carefully, those people will rule the world in future. Also, a degree in a field will teach you a lot of theoretical stuff, which might seem boring, but will be extremely useful in real life. Those who learn from the mistakes and wisdom of others are the winners.
The graduate degree is always useful.