Oil is not allowed at all in Neapolitan pizza dough per AVPN standards. That's why you don't see it. Depending on the kind of pizza you're shooting for and what your baking scenario is, it could do something beneficial for your dough or not. Some of us, like myself, rarely if ever use it at all, except in a pan when doing thicker styles of pizza. It's used quite often in NY style pizza dough at a rate of 2% to 5%, mainly to control the rate at which the water in the dough is released during the bake.
In my opinion, it's most practical use is in high volume pizzerias where maximum efficiency is desired, from the standpoint of both maximum dough volume and fastest bake time. If you want to get the most bang for the buck with your dough, you use as much water as possible to create maximum volume per batch, bake at the highest temp that's practical for staff to keep up with, and target the oil content so that just enough water is released in the bake without risk of burning the crust, and pull the pies out at just the right time. The risk is that oil itself can also burn if enough of it is used in the dough (especially if the pies are baking directly on the oven floor), and the bake temp is especially high, and that can create issues on the oven floor. For home bakers, I don't really recommend using it until you've run enough recipes without it to determine that you might need it. That's my take on it.
