Yes. It is.
But so is everything if it is used the wrong way! Think about each aspect of business. Even customer service is a waste of time if the people answering the phones are ornery and incompetent.
With that being said social media can be used as a powerful tool to enhance your marketing efforts and reach any goal. Although you need to use it effectively and efficiently. It is not a waste of time if you use it properly.
You shouldn’t use steel wool to wash your car. Nor should you use a squeegee to wash a grimy pan. Wrong tool for the wrong job. Do you want to sell, sell, sell? Go away. Social media doesn’t want to hear that. Relationship first. Selling after.