edition.cnn.com
Basically, if there are many food retailers in Venice, they will compete to serve more delicious food with lower price.
But, actually, it's not the case. It means that Venice doesn't have enough restaurants to serve tourists.
So, what the local government of Venice has to do is to financially support those who want to open osterias or restaurants.
Otherwise, Venice will have bad reputation about attitude of welcoming tourists and then will lead decrease of tourists turnout. Before that, Venice has to take measures for tourist traps to maitain its worldwide fame.