You're right on the label though, Italian American =/= Italian in the same vein that Chipotle/Taco Bell isn't Mexican. However, there are plenty of institutions in the states that do nail a more purist experience of Mexican or Italian or what have you.
Tex Mex or Cajun cuisine would be a more apt comparisons.
There’s something very unique about the US, which is that we’re taught from a young age that “culture” is something that other places have and the US is just a melting pot. But you can’t mix things together for 200+ years and still seriously claim you haven’t created something just as unique as the ingredients that went into it.
Maybe those things are conflated in places with no direct connections, but any Italian American with ties to Italy knows that the two are very distinct cultures.
https://www.atlasobscura.com/articles/how-capicola-became-ga...
E.g. many staples of Chinese restaurants in America (General Tso's chicken, chop suey, sweet and sour whatever) are not found in China except at super touristy places.
Since it's early morning as I write this, I'll use Hong Kong-style macaroni soup[1] as an example: it's literally macaroni in broth with a slice of processed ham on top and some white bread on the side. Not Chinese in the least, but now it's as much a local breakfast staple here as congee.
Also, an aside: sweet and sour pork is a legitimate Cantonese dish and it's in every Canto restaurant in China. I really miss crab rangoon sometimes, though...
1. https://medium.com/@xinwenxiaojie/in-praise-of-hong-kong-mac...
On the other hand, it's probably just culture diverging and developing in different ways after migration, which is to be expected. So the problem is mostly one of identity: the same label - italian - means very different things to people across the world...