But regardless of the why. Let's be more specific: New York is one of the most diverse cities. Let's say you want to make New York less diverse. How would you do that without forcibly relocating people?
https://www.washingtontimes.com/news...-rahm-emanuel/

That we’re cutting off funding for schools, cutting off funding for police, allowing people to be forced to live in food deserts, closing hospitals, closing access to mental health facilities. What choice do people have but to move, to leave?” Mr. Kennedy asked.

“And I think that’s part of a strategic gentrification plan being implemented by the city of Chicago to push people of color out of the city,” he added. “The city is becoming smaller, and as it becomes smaller, it’s become whiter.”
TBH Oskar, I'm not sure why your question of "how" is all that compelling. Gentrification is not a new concept. The playbook already exists. So, what's your point?