It makes quite a lot of sense to focus on reducing the risks of every human everywhere dying, rather than the risks of already existing oppression getting worse.
No, you are deeply misunderstanding the issue. Creating a rivalrous good that powers fight over for control, then use violence to maintain control of, creating a global feudalism, is not "existing oppression getting worse". It actually makes the risks of every human everywhere dying far higher, and even if that doesn't happen, decreases global utility by a similar percentage (99%, instead of 100%). It could actually be worse, if average human utility becomes negative.