I kind of disagree. People compare The Terminator sometimes to Halloween, as a slasher film with a silent hulking relentless killer.
But the amount of extra things James Cameron added to that template is pretty staggering...
The movie succeeds massively as a horror, an action film, a sci fi film and a romance.
He fleshes out the future world with a great deal of lived in backstory, like dogs being able to spot Terminators (and it coming in handy later on in the movie). Few writers would bother with a detail like that.
The love story is moving. The time travel paradox is interesting.
Again, with the level of detail in the backstory, the Terminators are on the 800 series because the previous models weren't convincing enough. How many writers would bother with that in the first movie? The 600 series had rubber skin. Even what isn't said is interesting. There were models before the 600 series, and something came between the 600 rubber skin models and this T-800.
Then there's the notion of technological / AI defeatist determinism and the implicit warning about all the shit we're doing today with technology.
If all James Cameron wanted to do was have a robot coming after and killing people, he could have gotten away with a lot less thought and hard work.
But thank goodness Dani Ramos is here to fix all that.