This is a nice graphic that, if anything, is optimistic.
What if trucks stopped running? Trucks are part of the backbone and all of the last mile of the supply chain.
Once the supply chain fails, food disappears very quickly (less than 24 hours) from hoarders (of which I would be one).
Society breaks down very quickly from there. Within a couple of weeks you have food riots, and people killing to survive.
Most people don’t realize how quickly this can happen.