I never watched the alien series, probably because you kinda know going in everyone gets eaten, so why invest any feeling in fictitious people who are due to expire?
Sounds like the Aliens industry has discovered that audiences simply like to watch people get eaten by aliens.
You can reduce the plot of any story to make it sound lame.
Romeo and Juliet: two horny kids from rival families fall in love and die in the end via misunderstanding.
A Christmas Carol: old guy learns lessons in greed and generosity.
Grapes of Wrath: poor family strives to survive, but fails because the system is rigged against them.
Etc.
The original Alien is a masterpiece of suspense, atmosphere, design, and originality. Every film in the series following it is so inferior because none come close to reproducing the original in any meaningful way.
Watch the first one and feel safe in not watching any of the others.