Personal auto insurance is designed for drivers that are using their vehicles for their own use, and not for business and/or profit. Some things may seem like their for profit, but aren’t considered a business activity. For example, driving to work is something many people do every day, and they drive to work to make money, but it’s not considered a “business”.
So you can drive to work, including to a pizza delivery resturant, and have confidence knowing your personal auto insurance will cover you in case of an accident. On the other hand, delivering pizza’s once you arrive is considered a business activity and you’re likely going to be out of luck if you get in an accident and ask your personal auto insurance carrier to pay for damages. That’s what commercial auto insurance is designed for. To cover activity that is business related.
It’s easy to understand why there are two different types of auto insurance when you think about when, where, and how much people drive for business reasons (like delivering pizzas) compared to driving for their own personal use.