Perhaps you're not aware that the number of Italian-Americans is almost half of the population of Italy. My two favorite pizza shops in my town? They're both owned and run by Italian families. This is the norm, not the exception. They even grow their own tomatoes! This isn't always the case for the national pizza chains, but you'll be hard-pressed to find an American claiming these chains are their favorite pizza (sadly, they do exist - but they're not the majority!)
It was Italian Americans who developed the New York Slice. It was Sicilians who developed the Chicago Deep Dish. You call it cultural appropriation. I call it immigrants bringing their food with them and further developing it.
Does that make pizza American? Well, I've noticed most of what the english-speaking world calls "pizza" is actually a pizza of Italian-American origin, not the Neapolitan pizza hailing from Naples. I think this is what the OP was referring to.
Things have changed! I did a search of best pizza in London and all the pies pictured, save for one, was definitely Italian pizza. The one that was not was described as US-style. On the plus side - it looks like you have a lot of great pizza available to you! You can even get US-style pizza if you so desire and thank goodness it appears to be my favorite kind of American pizza - the NY slice! (they claim you can get it at Joe Public). I have the opposite problem - getting a bona fide Italian pizza in my part of the world is difficult. Then again, getting a good NY slice is difficult around here. I'm in the U.S. Midwest and our local pizza options are dominated by the Chicago style, Detroit style, and Columbus style. But the NY style and Italian styles are my favorites! You've got it made, mate!
It was Italian Americans who developed the New York Slice. It was Sicilians who developed the Chicago Deep Dish. You call it cultural appropriation. I call it immigrants bringing their food with them and further developing it.
Does that make pizza American? Well, I've noticed most of what the english-speaking world calls "pizza" is actually a pizza of Italian-American origin, not the Neapolitan pizza hailing from Naples. I think this is what the OP was referring to.