It’s a little jarring seeing a post like this alongside a post celebrating the possibility of jailing people for doing a nazi salute. Anyway to answer your question, some people cannot function in society. They are dangerous, and the only way to prevent them from harming others is to isolate them from society.
Do you think it’s possible to live in harmony with the rest of the world? If the united states conceded its powerful position, who would take over as the new world power? (Probably China) Would you be better off? Would the world in general be better off with someone else in charge? Would you prefer to stand for the Chinese flag or the American flag? Or do you actually think we are ready for a world where there are no super powers?