Sober thought
So technically, pepperoni IS a form of sausage. People get sausage and pepperoni pizza but really its sausage and sausage.
But would you want a pizza with thin sliced italian sausage and pepperoni crumbles?
I would disagree, respectfully of course.
Sausage is a fresh meat product.
Pepperoni, salami, prosciutto, etc are cured meat products.
pepperoni is sliced thin because it has a much tougher consistency than a fresh sausage. As such, the thin slice makes the slightly dried/degreased pepperoni more palatable and easier to consume. Chunked and oven baked, dried/degreased pepperoni would be far too difficult to eat, thereby ruining the pizza eating experience.
It might as well be square cut thin crust.
speaking of cured meat... just put on a brisket for tomorrow night’s pastrami.