Pizza is not a problem provided you know how to counter the inevitable spike in blood sugar. But you do need to be on insulin to have a chance of doing so, ideally with a pump so that the meal bolus can be extended for the correct amount of time. I am "lucky" to be in this club, and can maintain a flat bg level of below 7 in this way, but it did take a few dire mistakes to get to this point!
Also I make my own pizza dough (SO much better than bought), and that way can be certain how much and what type of flour to use. My 12" pizzas contain just under 60g of carb, but I do appreciate that even this "moderate" quantity is too much for some.