Bread, cheese, and tomatoes have all been around since ancient times. So, why did it take so long to invent pizza?

Sans the tomatoes (from the Americas after all) Pizza has been around at least 2000 years ago: https://www.reuters.com/lifestyle/pizza-painting-found-ancient-roman-ruins-pompeii-2023-06-27/

We also have a written account of Persian soldiers using their shields to bake a flatbread with cheese and dates on top from the 6th century BC, which one could count as Pizza.