I think that the question is really, really broad. “Netflix” covers a lot, and “Americans” covers a lot, and “how someone talks” covers a lot.

Movie scripts are going to have more time spent on them than text that someone comes up with on-the-fly. They have carefully-crafted one-liners. They have professional actors, who are often going to be, say, better-looking and more-suave sounding.

On the other hand, relative to English in whatever country you live in, there probably is slang and any number of things local to the US that does show up in Hollywood movies more than in your country.

So I think that any answer pretty much has to be “yes…and no”.

If you can narrow your question down to a very specific, like, oh…“do people actually say X in the US in real life”, you might get a more-meaningful answer.

TVTropes has a whole list of things that people do on phones in film, for example, that typically aren’t reflective of real life. To choose one, people on one end of a phone call repeating what the remote person has said so that the audience can hear it. People don’t do that in real life; it’s a technique to help storytelling in movies.

Or another one of my favorite quirks — I like a lot of military history. Often, you’ll have war movies where very-expert characters, like General or Admiral So-And-So, will basically be explaining big-picture things in very basic terms to each other on some kind of pretext. That’s for the benefit of the audience, so that the characters can basically act as narrators for the audience. That wouldn’t be done by those characters in real life.

But that doesn’t mean that real American culture and mannerisms aren’t present in movies.