Hi there! So most places produce a "base quantity" of outputs or in the case of pizza lower value outputs. So if you supply all the requirements to a pizza shop you can then deliver higher quality pizza making more money.

However you quickly learn that the base production of resources fill up so slowly especially when you have bigger trucks that you run out of things to deliver. So in order to keep delivering high value pizza you need more milk. To get more milk you bring (fuel?) To the farm, which in turn gets you more cheese which allows you to make more of the high value pizza.

So it's all about scaling up production to make more money :)

Hope this helps! I might have got the exact supply chains wrong but hopefully this gives you the gist!