It was indeed not so. From the point in time I was summoned, the world had endured a calamity that drained it of all its mana decades prior. The only reason a Holy Grail War existed was because of a crystal acting as a powerful computer deep beneath the lunar surface. Spirit hackers -- the magi of the new world -- would use avatars to insert themselves into an artificial world and summon Servants there. The Holy Grail War there was a tournament permitting the participation of no more than 128 Masters, each partnered with the Servant they had summoned.