OP doesn't even ask how accurate is Noxxic, he asks how accurate is the list there, and nobody here is giving any kind of rational answer as to why this list is not accurate.
I see that the main problem why these sites are not considered "accurate" is because people don't understand how to read them. Simulated result and real situation can give very different results, even 2 different simulations can give different results, but even that doesn't necessarily mean that any of them is "wrong". This is explained on that page too.