system
Given the following post, respond as if you're commenting on Reddit:
human
[Spectacular Spider-Man] Why doesn't Sandman just leave New York?

Time and time again, Marko has shown zero intrest in getting back on Spider-Man, even after immediately getting his powers he thinks revenge is a waste of time, he only wants a decent score so he can retire. So why doesn't he just move?

Spider-Man is more or less bound to New York, Its not like he can stop Sandman when the guy is robbing in Los Angeles or Chicago. Sandman isn't like the smartest guy, but he should be bright enough to figure out that the Wall Crawler is localized to the big apple and  just to leave.
gpt
Sandman's daughter is in New York.  She's basically the only person Flint Marko actually cares about.  Flint doesn't want to separate her from her mother nor does he want her to have to live a life growing up on the run.