The ending of Black Panther (2018) has T'Challa defeat Killmonger, who chooses to die rather than live in captivity, and then turn Wakanda away from isolation.
After the fight in the vibranium mine, Killmonger refuses to be healed and dies after seeing the Wakandan sunset. T'Challa then sets up an outreach center in Oakland, at the site where N'Jobu died, to be run by Nakia and Shuri.
In my opinion, the location is the most important detail. The brothers' confrontation took place in Oakland in 1992, and the film closes there with an act of repair, so the story ends where the original wrong was done. It could be argued that T'Challa wins the argument by taking Killmonger's grievance seriously while rejecting his method of shipping weapons to start uprisings.
The structure supports that reading. Ryan Coogler and Joe Robert Cole open with Oakland, send the middle of the film to Busan, where the stunt team shot the car chase on the city's streets over about two weeks according to Screen International, and then return the finale to Wakanda. Much of that Wakanda, including the Warrior Falls set where Killmonger throws T'Challa over the waterfall, was built in Georgia. Because the ritual combat happens on a constructed set rather than a vast CGI field, the two fights read as personal duels, not as the army clashes that close films like Avengers: Age of Ultron.
The choice also reshapes what comes next. T'Challa ends the film as an open and public king, and the mid credit scene at the United Nations confirms it, while the post credit scene of Shuri helping Bucky Barnes shows Wakanda already acting as a refuge. Perhaps the cost of that openness shows up in Black Panther: Wakanda Forever, which begins with Wakanda under pressure from other nations that want its vibranium. Compared with Captain America: Civil War, where Boseman's T'Challa was driven by a personal grievance, this film lets the same character answer a grievance with a policy. Whether you read the ending as hopeful or as a risk, Killmonger's refusal to be saved keeps the film from feeling tidy, and that is the reason I think it holds up.