A half answer, and half question, but what part of the first section of the film do you not think is present anymore?

The arc follows a training company through Marine Basic Training at Paris Island South Carolina. And for the time it depicts relatively normal portions of training. And still does today, close order drill, formation PT, basic marksmanship, obstacle courses are all still around as part of training today. Even the collective punishment, just minus the outright physical abuse, while R Lee Ermey as Gunny Hartman was famous for his depiction. He ad libbed much of his role based on his years as a Marine Corps DI, and in a bit if life imitating art whole generations of Marines have seen the film, loved it, and tried to imitate hus style and performance.

So yes it was pretty accurate to the experience of Marine Basic, and no it didn't really go anywhere.