The Alien, Terminator, and Matrix franchises have similar problems.
Aliens successfully changed genres, from horror to action. But subsequent movies could never recapture the primal horror of the original or the fun action of the second. It's almost like there are only two local optima in the Alien movie universe and Alien + Aliens took them both.
Terminator is the same. The first movie was a perfect sci-fi action movie, with a trippy premise and loads of fun. The second was a subversion of the first: the Terminator is the good guy! And that worked too. But after that, where else can you go?
And, of course, they never even bothered to make sequels to The Matrix.
Aliens successfully changed genres, from horror to action. But subsequent movies could never recapture the primal horror of the original or the fun action of the second. It's almost like there are only two local optima in the Alien movie universe and Alien + Aliens took them both.
Terminator is the same. The first movie was a perfect sci-fi action movie, with a trippy premise and loads of fun. The second was a subversion of the first: the Terminator is the good guy! And that worked too. But after that, where else can you go?
And, of course, they never even bothered to make sequels to The Matrix.