How is this different from an online food ordering and delivery platform like the big apps?

The page is yours. Customers order on your own address, the order comes to you on WhatsApp from your own number, and they pay you cash or on your card machine when the food arrives, with no commission on the order. The apps are not shut out: connect them under Settings → Delivery apps and their orders arrive on the same board and the same kitchen screen as your own. So the apps bring strangers and your page keeps the regulars, with the loyalty card on their phone and your promotions pulling them back to it. The Orders & delivery tab in the docs explains the flow from the customer's side.