Britney Spears did it. So did Kim Kardashian. But that doesn't necessarily mean annulling your marriage is an option for everyone.
Divorce is a legal end to a marriage but annulment is a different process. At the end, it's as if the marriage never existed under the law. That allows you to avoid the division of property and distribution of alimony that comes with divorce.
To call annulment an alternative to divorce isn't quite fair. You can end a marriage for any reason, or none at all, with a divorce. But you can only get an annulment if you qualify.