As someone who walked down 116th Street in Manhattan yesterday, I can assure you there is a large and healthy immigrant population here coming from Africa
Also, much of the African immigrant community you see in NYC is primarily Senegalese in origin (there's a reason why 116th St in Harlem is Petit Sénégal), and most Senegalese immigrate to France.
There are only around 20k Senegalese Americans (most of whom live in the NYC area) versus 300k French Senegalese. And that's just Senegal alone.
NYC is not representative of the US, and you don't see the same degree of immigration of Africans in the US aside from isolate communities such as Somalis in Minnesota, Tigrayans in the DMV, or Igbos in tech hubs and TX.