> I feel like sortition is much closer to direct democracy because the distortion is limited by the law of large numbers and can be exactly calculated.
No, it can't. The likelihood of a particular degree of distortion (sampling error) can be exactly calculated; the actual degree of distortion cannot.
That is true, but you could argue that the same is true with elections. What if everybody that wants to vote in a certain way is sick on election day? Not very likely, and of course in case of elections the number is larger and therefore the probability of (this specific type) of distortion is much smaller. But then one is again talking about probabilities. And in case of elections there are many other arbitrary factors that can influence the results.
No, it can't. The likelihood of a particular degree of distortion (sampling error) can be exactly calculated; the actual degree of distortion cannot.