worth a read
https://hackaday.com/2020/08/12/the-ever-accelerating-automation-of-fast-food/
When I delivered for Domino's in the mid-1980s, everything was made on-site. The baker came in a 4am and started making dough from water, flour, yeast and salt (that is the full ingredient list). He left about when we got there. Pizzas were rolled out and hand tossed, just like in a traditional pizzeria. The sauce also had four ingredients listed: tomatoes, oil, salt, spices. When we got low on beef or bell peppers or whatever, one of us stopped at the grocery store on our way back from a delivery (though most of them, of course, came in bulk on a delivery truck, but it was the same stuff).
I haven't had a Domino's pizza in 30 years, but I'm betting none of the above is true except perhaps having driver's stop at the store when toppings run low. But I wonder about that. I bet they just tell customers that they're out.