So? Reddit has about 10 sizeable Subs that are just a variation of “Ask Any and All Questions”. That’s not even counting speciality subs like “MedicalQuestions” or “ITQuestions” or “DermatologyQuestions” or “AskTrangender”. Or the different language ones like “FragReddit” (German). In the end 1-3 will become the major ones, all will be a bit different and everyone will find the ones they like most.

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.