The moral vacuum that we live in has driven us to seek an answer to such a simple question. The answer is: it is only worth it for you, if you feel that marriage has worth.
It would be no different than asking "Houses, are they worth it?" "Since so many fall apart and require maintanance, is it worth investing my money and time into one?"
Since ethics are not taught anymore, and religion (the layman's ethics class) has fallen to the wayside, society is forced to ask this question. Marriage does not provide anything in and of itself, it is simply a title. "I am married." It is no different than "I am a captain." If I have the title of captain, yet I am a drunk behind the wheel of the ship, how long will my ship and crew last? If I love being the captain, because I value what it provides me (personal joy, the power of command of a vessel, access to the seas, etc.) I do everything in my power to keep my ship in working order, because it is a major source of my happiness. The ship does not provide me happiness in and of itself, but of what I can do with it. Because a ship exists, provides me no pleasure, only when I take control of it do I obtain happiness.
Marriage is the same, it is simply a title, a declaration to the world that you have obligated yourself to one individual, one who you feel is a reflection of your values, and with whom you feel will provide you happiness in your journey in life. Simply being married does not further you in your goal, i.e. happiness, it is simply a contract, obligating you to this person.
If you value a person, because you value the happiness that their company and actions provide, then yes, marriage is worth it. If you do not value the companionship of a single person, if you prioritize variety, then no, marriage is not worth it to you.