I guess it depends on what you mean by "deep fry" ....
I knew a guy working at Pizza Hut, what they do is this, they fill their deep dish pans with a good 1/4" of oil. Yeah you
read that correctly. A good 1/4" of oil. The dough is then placed on top of the oil, and then put into their proofers.
When the pizza is finally put into the oven, it hits that heat and the oil heats up very quickly and in a way it's deep fried,
as the dough is actually sitting in a good thickness of oil, and there's plenty of oil there to totally brown / crisp that crust.
That's why it's so damn good
( in my opinion )
I'm referring to the pan pizza crust here, where they deep fry the crust.