You are missing the point of the comment entirely. They are trying to bring the statement "everyone being in prison" to a realistic context to better understand

You are missing the point of the comment entirely. They are trying to bring the statement "everyone being in prison" to a realistic context to better understand what it actually means and what it feels like to live in a place where "everyone is in prison". They are assuming the commenter is American or at least has an idea of what America is like, which is not a bad assumption to make on an English-language website run by an American company.