Because dumbass out of towners have this ignorant stereotypical concept of a New York accent. Not including the fact that people from different boroughs, backgrounds, ethnicities and educational backgrounds can cause the accent to vary. Depending on who your family or associations are, influences how we talk as well. There’s a lot that factors in. Queens is not going to sound like Brooklyn, Manhattan has a different dialect from The Bronx. Queens NY had the label of talking more “proper”. Staten Island is all those Italian/mafioso nasally accents from tv that people use as reference for whatever reason - think all of New York is like that bc they don’t live life off the computer. Black people don’t talk like Italians. Out of towners Watching a “hood vlog” and think we’re all on that “yo ayo dun” shyt - male and female.
The actors/actresses definitely use vocal coaches, dramatic training and receive training to adjust their accents altogether so that’s not a good example to use anyway. Why would you think entertainers are representative of people, duh- that’s a false comparison.