Why did One Piece Gol D Roger turn himself in?

Answer 1

Roger could have surrendered for the following reasons:
1. [Serious illness and no effective treatment methods]: Although there are demonic fruits in the anime that can cure diseases such as surgical fruits and healing fruits, Roger may not be able to be treated because of his terminal illness, so he chose to turn himself in and end his life. It was also possible that Roger's terminal illness was related to the overuse of rubber fruits. Even if someone treated him, it would not help. Although Oda didn't admit that Roger was a demon fruit user, there was a possibility that the rubber fruit was Roger's fruit and he gave it to the red-haired man after he died. The stronger the ability of the rubber fruit was, the more harmful it was to the body. Roger's terminal illness might be consistent with the consumption of life force of the rubber fruit.
2. [For the sake of inheritance and the opening of the great secret treasure: Roger arrived at the Final Island and learned the truth of the 100-year blank history. However, at that time, the things on the Final Island could not be revealed yet. He wanted future generations to dig them out.] After Roger and the others left, it would be difficult to find the big secret treasure on the unattainable Final Island without the inheritance. Therefore, he turned himself in to inherit something so that future generations could find the Final Island and open the big secret treasure.
3. [Unwilling to become a shooting star: Roger had great ambitions and didn't want to become a shooting star, so he chose to turn himself in at the last moment to end his life.]