1. The culture of NYC blacks differs greatly by neighborhood, sometimes by block. Harlem in the 80's and 90's was essentially a colony of the Carolinas with some PR's mixed in. Vs Bk, where the AA enclaves experience a steady erosion due to black immigrants. Harlem has since experienced the same, with black latinos (who are many) and Africans, less WI's.
2. ADOS have been shamed into submission. We used to be more resistant to the cultural changes engendered by proximity to other black ethnicities. The 2000's have been an era of assimilation for us. You could say it started slightly after the Bad Boy Era, say, Puffy and J- Lo time.
3. As a 2nd gen AA still in Harlem, I still see signs of us. If you hear music playing in the street in Harlem (a common occurrence), it's likely ours. Just the other day, I hear somebody playing Tevin Campbell.

And then a girl with a nice voice sang along as she walked, so it was double ADOS activities.
Or in the summertime, we still get trucks of old ADOS men who come from SC with boiled peanuts and other ADOS delicacies.
4. Our influence here is waning because we stopped seeing ourselves clearly, as our own ethnicity. We've been voluntarily subsumed. For example, we didn't know enough to consider the fact that letting our own salons die in order to, succesively, get braids from the Africans and then get doobies from the Dominicans, was not a good long term plan. In our naivete, we just saw them as black-adjacent, cousins. We didn't know both groups were shytting on us in, successively, French and Spanish.
I blame our pan Africanist elders. See, pan Africanism is cool as an ideology when you still have your own spaces. Instead, we jumped in with two feet. Ex: note how many old nikkas in Harlem still be walking around wearing "African" clothes like it's the damn 70's. They were ripe for the picking. During the period when the black immigrants were coming up legally, we were doing illegal shyt. Unlike the Dominicans, tho, we didn't know enough to launder the proceeds. Probably bc our elders didn't know, too busy protecting their families from the ravages of crack et al, ruminating on ancient Kemet, or program- pimping.
5. NYC itself. Being locked out economically for so long has it's effects. Watching everybody come in and get it has its effect, especially on our children. They've become increasingly mercenary, a pre-cursor of the money-hungry undercurrent of several modern black movements (incl black feminists and the new-to-us assortive mating). The same way the financial crisis, imho, stemmed from NY/ Wall St style, no-holds- barred capitalism* and filtered out to the rest of the country, NY style money- hunger has filtered out as well.
*my own theory, borne out by the fact that, by time the rest of the country could absorb what had happened (2016), the nominees of both parties were NY'ers, presumably more well- versed in the economic storm that had hit us.