Just like a theoretical Turing machine doesn't require a human to feed it with a strip of tape, a theoretical Magic-Turing machine doesn't require a human to feed it with tokens and damage markers.
And game-breaking infinite loops in Magic are dime a dozen. Did you know that there's a combo that allows you to rip every card in your opponent's deck into confetti? (Unless they forfeit.)
Sorry if I entirely missed the point of what you were saying.