From the mid 90s to early 2010s, NYC, particularly north Brooklyn, was known as the city to be in for people into indie music. This film tries to connect that with coverage of some key bands from the 2000 to 2005 portion of that era. It's mostly about those bands and less about the scenes in which those bands were a part.
Bands featured in order of the amount they were covered: The Strokes, Yeah, Yeah, Yeahs, DFA (especially James Murphy), Interpol, Moldy Peaches, TV On the Radio, The Rapture, and The Liars. There were more there during this time that weren't mentioned and obviously more after the period covered in this.
Iirc, Karen O notes how NYC started becoming too expensive and that making it more difficult for artists and musicians (and she later moved to LA and still lives there, she grew up in NJ). But some come from more privileged backgrounds and the film touches on that with some of the band members.
Although I was into all of this music then, I don't like how "indie" during this time shifted to whatever people in north Brooklyn are into. I prefer how things were in the 90s where bands from several cities got equal attention, including some pretty small ones like Athens. Some are trying to revive the era covered in this film, including the focus on NYC, because it's easy to just recycle trends from 25 years prior and pretend you're a trend setter, but it is far less affordable now than then.