I've worked in this field. In every sector there will be someone trying to game the system one way or another. Someone will publish a menu including items the

I've worked in this field. In every sector there will be someone trying to game the system one way or another. Someone will publish a menu including items they don't actually have in order to try to rank higher in a search ("oh, we don't have that any more, but since you're here, why don't you try X..."). Someone will publish a menu with lower prices to get someone in the door ("oops, Google must have an old menu of ours"). Someone will publish a menu including something with their competitor's name in hopes of hijacking their searches. A steakhouse will mark a steak as vegetarian in hopes of tricking someone into thinking they have a vegetarian entree. You'd be lucky if 50% of the restaurant supplied data is accurate, 40% is out of date, and 10% is actively incorrect. Personally I'd guess that the ratio would be more like 20/60/20.