Support for contributions is one of the most sought after features in FormBuilder because it allows users to take payments through highly customizable forms without the constraints of CiviCRM's traditional online forms. Control which fields display, their order, how they're related, etc. on online forms through a drag and drop interface, and then process payments through the form. It's a whole new level of flexibility for CiviCRM!
Your support (though this non-FormBuilder form) will help make that happen!