Mamdani is a win for everybody.
NYC got a better Mayoral option than a former Governor who was impeached (sorry - stepped down while being impeached) who also happens to currently look and act like a wax statue, and the Incumbent mayor who is openly corrupt.
Mamdani comes armed with a bunch of ideas that would not be out of place in many major cities in "the west" and a real knack for communication. I am skeptical of some (many?) of his policy ideas but none of them require the proletariat to rise up. He won't get magic powers either if he wins. He will face the same challenges to execute his vision as every other big city mayor must come to grip with.
His perceived success will come down to media coverage, his ability to actually execute on day to day city politics, and luck.
On the other side, the right wing warriors get to blame a non-Christian brown guy every time something goes wrong in NYC. It is a big city with the most expansive local media in the USA and so there will be a never ending stream of news to pick from: "white woman mugged on Subway" or "79 year old billionaire moves to Florida because he got his feeling hurt". I know that many of you are like fat kids in front a plate of cookies when it comes to that stuff. Enjoy.