Did I miss a debate
I've never used an uncooked pizza sauce either, whether I've bought a commercially prepared pizza sauce or made my own. It's cooked when it's made and then cooked/reheated on the pizza. It's typically more heavily seasoned than regular sauce because you don't use as much.
In these parts red gravy is simply a term for spaghetti sauce. It's not a common term, but you hear it now and then. And spaghetti sauce can describe the sauce no matter what it's going in or on. As in, "Put extra spaghetti sauce on my meatball sub". They'll know what you mean.
Sunday gravy to me is a sauce with the chunks of meat like pieces of pork or veal. Not to be confused with hamburger or sausage.
Tomato sauce is used to make spaghetti sauce. They sell it right in there with the diced tomatoes, chunky tomatoes, crushed tomatoes, tomato puree... all the endless array of canned tomato products. Some tomato sauce comes seasoned though, and that could be used on its own on pasta. I've never tried one I liked and it's usually thin anyway, so maybe it needs turned into a spaghetti sauce, or red gravy. Or poured over stuffed peppers and cooked for hours anyway.
And then there's the jars of Ragu, Prego, Newman's Own... I suppose those are a tomato sauce, but aren't they always preceded with an adjective, Like chunky garden, garlic and basil...? I wouldn't exactly call them a straight tomato sauce.