That's a bold claim. While I'm sure the average quality in Japan is significantly better than ours, I would put the best pizza places in Jersey, NYC, and CT up against anywhere in the world.
But Tokyo has a loooooooot of good food from various places, and a lot of people with money willing to spend 5 bucks a slice (for example). Or at least enough to sustain one restaurant.
The contrapositive: what magical thing exists in Jersey that would not be exportable to Tokyo?
I would bet that NYC has the best cheap slice tho.
I just don't think Italy _gets_ pizza the way America does.
"Italy" as a whole, I make no claims on.
In America it’s generally lots of ingredients piled on, with prices spiraling out of control.
Anecdote: on a recent trip to Nee York City I was momentarily excited to read about a place making Napoli style pizzas. Then I saw a pie was close to $40. In Napoli that was about €6.
However, when I only had a few minutes before a show I dove into the closest pizza place and got a giant NYC style slice for a little over $5. It was the best meal I had during that trip.
So I think the moral of the story is that the best pizza is the one from the shop closest to you done in the style that city is known for. At least if you’re in NYC or Napoli.