Both sugar and artificial sweetener are addictive. However, artificial sweeteners are more likely to make you feel hungry, eat more during the day, and develop diabetes. Sugar is fine in limited quantities and in the context of a healthy diet. Eating a cookie that you made yourself is fine.
By offering the sweet taste without calories, artificial sweeteners appear to be an answer for effective weight loss. An average 12-ounce can of sugar-sweetened soda provides about 150 calories, mostly from sugar. Same amount of diet soda, zero calories. The choice seems obvious.
Like artificial sweeteners, sugar alcohols are created synthetically (usually from the sugars themselves).