Many people didn't.
“Overall in New York City, Biden received 2,321,759 votes, 76%, to Trump’s 691,682 votes, or 23%; a margin of 1,630,077. In 2016, Hillary Clinton 79% won of the vote to Trump’s 18%.”
“Biden won the state of New York by a 60%-38% margin; compared to Clinton’s 58.8%-37.5% win in 2016, meaning that while Biden did worse than Clinton in the five boroughs he outperformed her outside the city.”
https://www.gothamgazette.com/city/9961-breaking-down-2020-vote-new-york-city-biden-trump
NYC 2020 Presidential election percentages:
Queens - BIDEN 72.2%
Bronx - BIDEN 83.4%
Brooklyn - Biden 77.0%
Manhattan - BIDEN 86.7%
Staten Island - TRUMP 57%
Nassau - BIDEN 54.2%
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You’re right, not everybody voted for Biden...............
DC 2020
Joe Biden/Kamala D. Harris (D) 317,323
Donald Trump/Mike Pence (R) 18,586
https://ballotpedia.org/Presidential_election_in_Washington,_D.C.,_2020
In total, Biden received 5,230,985 votes (60.9 percent) in New York to Trump’s 3,244,798 (37.7 percent) to claim the state’s 29 electoral votes.
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In Suffolk County (Long Island), the incumbents tallied 381,253 votes (49.4 percent) versus 381,021 (49.4 percent) for the challengers.
In Nassau (Long Island), Biden and Harris received 396,504 votes (54.1 percent). Trump and Pence garnered 326,716 votes (44.60 percent).
Results above are from the 2020 election. Suffolk was a dead heat assuming it was honest which I do not.