The problem I find with any reference to 'US pizza' - is it's an impossible comparison. There is, of course, no such thing. There are approximately 407 different pizza establishments in every small city in the US, and they all make their pizza differently. One thing the US doesn't lack for, is variety in its pizza offerings.

It's the same problem that crops up when foreigners proclaim that American chocolate is horrible. Which of the countless different domestic brands? They think Hershey's chocolate is the primary chocolate Americans can buy, it's amusing. The same thing happens in discussions about cheese.

It stems from most nations having small consumer & manufacturing economies, small numbers of suppliers of things. It makes it difficult to understand or relate to the enormous scale of the US consumer market (so large it produced Walmart, a $523 billion sales behemoth that is as big as the economies of Poland, Belgium or Sweden). The only proper consumer & manufacturing scale references are to the entire EU or China. It's almost the equivalent of saying pizza in the EU is good or bad; or cheese in the EU is good or bad. It would make absolutely no sense.