Let's think about the latest Biden +14 poll. What is the probability of this actually happening? It would mean Biden would likely win 49, or maybe even all 50 states. A Reagan like landslide.
Maybe Biden wins, maybe he loses, but I would guess the probability of him winning by 14 points nationally is near 0.
If a poll produces a result that would be impossible to actually occur, the poll is clearly flawed and should have been scrapped.
The poll does not say that Biden is going to win by 14. It says he is leading by 14 at 53-39. The RCP average shows that 10 of the 11 polls show Biden at 49% or greater. with 9 of the 10 showing Biden at 50%.