To say this article is an oversimplification is a severe understatement. There is not one, but a string of middlemen between a farmer and a retailer. If you eliminate them all, how are products (not information but real products) move from a farmer to a retailer? By smartphone? Each farmer is going to transport his own tomatos to a retailer 300 km away? And who is going to pay for all the sensors? Why is nobody investing in them now? Middlmen do not want to earn more money?

In XIX c. there was a solution, called cooperatives. They managed to get things done no blockchain can accomplish — apart from access to finances, insurance etc. they were able to move real goods, not just information.