In Logon, Wolverine starts losing his healing power in the dark future timeline. Here is the reason why he got sick and his powers went asleep.
The Mutant Story – Logan
Wolverine lives in a dark future in Logan and is seen to be slowly losing his mutant healing powers. This apparently leads to his tragic death. The R-rated and Academy-nominated film, Logan, is the last time Hugh Jackman portrays Wolverine on screen. Directed by James Mangold, this role made Jackman world-famous, thanks to the X-Men franchise. While the film laid some foundation for an explanation, Logan didn’t explain how Wolverine loses his healing powers.
The film is set in 2029, a timeline where the X-Men has been killed off. As a result, no new mutants were born in the last 25 years and the ones who were already there were hunted by the evil Transigen corp. It was James Howlett’s Wolverine in Logan who was living as a chauffeur. He also works to take care of Professor Charles Xavier who is also a mutant telepath, but dying of brain disease. Wolverine gets shaken out when Laura, a young mutant girl, shows up to take care of him and Professor Xavier.
At the beginning of the film, Wolverine is seemed to be clearly ill. He has been alive for almost 200 years now. This has been possible because of the healing ability that made him almost immortal. But in Logan, his powers seem to be getting less effective. He starts becoming addicted to painkillers and alcohol to endure pain. With his powers declining, even his claws fail to come out as quickly as they once did. But why are his powers failing? The reason is pretty much straightforward: Adamantium poisoning.
Once that Wolverine confronts a mindless clone of himself who killed Professor X, he gets wounded. As a result, Laura takes Wolverine to a local doctor. There, the doctor told him that there is something in his body that is killing him by poisoning inside out. Logan guessed that it is the Adamantium coating applied during the Weapon X program. While the government experiment made him a powerful weapon, it also opened a portal to his demise. Thus, it remains unclear how long he could survive without the operation.
The film didn’t elaborate much about Adamantium poisoning. But it can be summarized that Wolverine had a very long life because of his healing factor that eventually went through a breakthrough. The Adamantium was continuously poisoning him. As a result, his healing powers started failing gradually. Thus, by the time Logan was released, there were not many medical resources available for the mutants. Even if there were, the bonding process of Adamantium could not have been reversed. Hence, by the end of Logan, Wolverine’s healing powers depleted and could no longer save the mutant from the pain and wounds. With that being said, Wolverine died of having fatal injuries and that is how Jackman moved on from portraying Wolverine.
Source: Screen Rant