I pretty much agree everything stated above, even down to the Terminator observation.
I believe the mistake made was the film’s direction after Alien. They kept trying to replicate the story formula for two following sequels. How many times do we have to get Ripley stuck in some situation, having to coordinate how to snuff out the Xenomorphs (usually the same plan), where one by one, each character gets killed, surprise-surprise.
It would had benefitted the franchise to focus on The Company, and what their deal is. I guess the modern spin-offs tried to do this, though to sub-par standards. Or let Alien exist as one contained film.