The issue isn’t one of format, it’s distribution. Menu data is usually in hard copy form, and the utility to a restaurant in going to the trouble to duplicate

The issue isn’t one of format, it’s distribution. Menu data is usually in hard copy form, and the utility to a restaurant in going to the trouble to duplicate it online and keep it up to date is almost certainly not worth it (in their eyes). So I’m sure you could sign up yelp and google and Uber eats and everyone else for a common data standard, but you’d then still have to go chasing the restaurants to go put that information in a system somewhere. We haven’t even really been able to convince businesses to put their opening hours online, it’s still such a problem that one of my interview questions at google in 2018 was “name as many ways as possible you might be able to discover a business’s opening hours online” Menus are about an order of magnitude more complex than that - it’s a tough thing to get restaurants to do.