Ok. Looks like you’re using gross profit while I’m using net profit. And I’m not including franchises like McDonalds or Wendys because most of the profits are from franchise fees and the raw products that their franchisees have to buy at a markup. They also don’t have employees that rely on tips and their portions tend to be smaller than a meal at, say, a Denny’s which does use employees that rely on tips.
I did pull up the link and it only showed the profits from a single corporation that owns Burger King and Popeyes. Brinker who owns Chili’s and Maggianos has a net profit of 2.48%, Denny’s has a net profit of 8.25%, Dine Brands which owns Applebee’s and IHOP has a net profit of 9.03%. And these are established restaurants that have been around a long time.