I think this just applies to the commercialized versions of those foods in the foreign countries. The pizza you linked to from Mexico looks like something you would get from any fast food pizza place in America and the Italian one looks like a margherita slice from any half decent pizza place in NYC. Same goes for the tacos. The "American" one just looks like something you get from Taco Bell while the "Original" looks like something I would get from a local taco truck.
The burrito is an interesting case. I do think that's evolved a bit in America to the point where everyone is copying Chipotle and Qdoba and trying to make the biggest burritos.
The burrito is an interesting case. I do think that's evolved a bit in America to the point where everyone is copying Chipotle and Qdoba and trying to make the biggest burritos.