The fact 538 considers the NYT/sienna polls the most accurate tells you all you need to know about 538. It’s not even close the the most accurate
Siena was wildly inaccurate in the last couple of President races. However they were one of the most accurate in the 2022 midterms, according to Silver. That seems to be what he’s going on.
How could they have been so far off and then suddenly been so accurate? One possibility is that they lied in the President races, but played it straight in 2022. Another possibility is that Trump polling will always be off, because of the unique factors related to him.