That seems like a badly phrased question, but what makes you think that is an inaccurate representation of how those polled answered it, or that it's inconsistent with the other answers in the same poll?
Do you think more and better information would make people think Biden is cognitively fit? (I doubt it would make much difference to the question about truthfulness, which is likely biased by a correct perception that politicians lie and a poorly worded question.)
Yes, actually, as he's been giving off the cuff interviews and press conferences for a while now that barely get covered.
"A correct perception that politicians lie"
It's only correct in the most pedantic way, a side effect of media refusing to call Republicans (and Trump) liars.