The thing about segregated places in the US, is that they never happen organically. Segregation is maintained by violence.
There's a direct line between present day Massachusetts segregation, its history of sundown towns, and its more recent history of white young kids violently assaulting non-white people just trying to live in the neighborhood.
This scene of Good Will Hunting is fake.
https://m.youtube.com/watch?v=i6zhqOcfqQA
In real life, it's this:
https://youtube.com/shorts/N5XE4sdxdaI?feature=share