When you receive a basket of "never-ending" bread at Olive Garden or "unlimited" Cheddar Bay Biscuits at Red Lobster, you get a specific number of breadsticks or biscuits.
Your first basket contains one piece of bread per person plus one extra. Additional baskets are available upon request but contain only one piece of bread per person.
This approach slows down diners' consumption of breadsticks or biscuits, especially as they fill up on other carb-heavy foods like pasta and potatoes.
The faster a restaurant can fill diners up, the less bread they eat. Bread isn't that expensive, but every saved penny counts for restaurants striving to make a profit.