I forget where I read it but one author said that mountains of ink have been spilled debating why quantum effects disappear at the quantum level. I don't understand why this is a problem, I think the answer is rather obvious. One poster on another thread wrote: "Technically - classical physics is what QM does on average ... so the math is different." https://www.physicsforums.com/showpost.php?p=4158638&postcount=2 That seems to be the answer. If the Planck length were roughly the size of a human being and a scientist was 10 orders of magnitude larger than a human, then if you continually measured a million humans, and your measuring device was rather crude, then each millions of human would be on average the same, even though a quanta (a human being) would not be the same but uncertain.