Warning: MAJOR SPOILERS ahead from Star Wars: The Rise of Skywalker. And Endgame, of course.
For Avengers: Endgame, it's Thanos vs. Tony Stark, with Iron Man getting the last word before winning and then dying. For The Rise of Skywalker, it's Palpatine vs. Rey, with Rey getting the last word before winning and then appearing to die (however briefly).
Thanos: I am inevitable
Tony: And I am Iron Man.
Palpatine: I am all the Sith.
Rey: And I am all the Jedi.
Star Wars: The Rise of Skywalker added a final twist to have Kylo Ren basically un-Snap Rey, being the one to die himself in a sacrifice at the expense of his own life. So he was the one who died a hero after that redemption that not everyone wanted him to have. And then Rey, like Captain America, ended the film by going off to start a new life. (And yeah, you could also add a comparison to Harry Potter getting a visit from ghosts of his past to lend him strength before he "died," just like Rey.)
At any rate, the Endgame/Skywalker quotes were very similar and many fans noticed.
They even had similar pauses before their big mic drop one-liners. I'm not suggesting Disney copied its scripts, although I've seen that snarky quip out there. (An actor from The Mandalorian also called Episode IX "an absolute fucking failure" and the worst Star Wars movie.) I still liked good chunks of Rise of Skywalker, and I mostly agree with the CinemaScore it got from fans polled on opening night. But it did strike me right away watching that Palpatine/Rey scene that it felt very similar to the climax of Avengers: Endgame.
Hey, there are worse movies to emulate than the highest-grossing movie of all time. If only Star Wars: The Rise of Skywalker also had Avengers: Endgame's box office and critical and fan acclaim. So far, The Rise of Skywalker is poised for a huge opening, and it will almost certainly top $1 billion worldwide in the end, even if it doesn't make as much as The Last Jedi or The Force Awakens. But it will not rival Endgame at the box office. If it somehow does? Remind me that I wrote that.
Star Wars: The Rise of Skywalker just opened in theaters and not everyone has seen it yet. Those who have seen it are discussing various WTF moments and places where J.J. Abrams and Rian Johnson were clearly on different pages. As the 2019 movie year winds down with December's many releases, keep up with everything heading to the big screen next year with our 2020 movie release date schedule.