Sure, but generally because the aggregated polls were systematically off. You may be thinking of other examples, but the 2016 US presidential election really wasn't that bad of a look for 538, they had Trump at reasonable odds going into election night. It's not like he was at 5%, 538 pegged him at 1/3 odds as polls opened if I remember correctly.
It's on the aggregate of predictions that you can see the accuracy. If my weather app tells me hundred times there is 10% change of rain but it rains 50% of the time after 100 days, it's completely useless.
Same for FiveThirtyEight. They have been massively wrong on multiple counts.
