Almost all of the cuisine known as “Mexican food” here in the U.S. was developed in Texas, NM and Southern California. Each of those regions has created several styles of their own.
Go ahead, go to Mexico, get away from any Americanized resorts, and try their traditional dishes. They’re bland and uninspiring. You won’t find anything you recognize as “Mexican food” there. Only superficially anyway.
I will say this - Mexican cheese is far superior to American cheese on tacos. I always use the Mexican cheese (the white cheese that crumbles). Also their taco sauce is much better.