According to wikipedia, there is rougly 2.5 Billions of Christians with half of them being catholic, moreover the Catholic church is a relatively centralised religion giving a lot of power to the Pope compared to other religious leaders. So I can’t think about many religious leader having that much global authority.

I Wouldn’t be surprised that the death of Ayattolah Khamanei will also quite a big news. However, while pretending to be “a religious leader” he is also the de facto political leader of Iran