Could we create open standards? Yes. Will businesses? Probably not. A lot of 'apps' for food act as an aggregator, which is the closest I can come to an API. But they are locked into one provider - hell, even getting opening hours, menu and how to pay standardised is hard. These all have standards available. No one uses them enough.

Why not? Technical difficulty - my local pizza shop doesnt care about running a payment processing endpoint, structured data, etc. Its counter to their goals.

What we need is an open source point of sale system that is web first - oscommerce with a desktop UI kind of thing. Then it becomes easy to add in 'publish standard compliant data'