I watched half an hour or so of that Nico biopic
and found it quite dull. I think the actress did a decent impression of her singing, for what that's worth. But it seemed like its main gimmick was juxtaposing people talking about her past with her being bored or cranky, and it didn't seem to me like there was a lot of mileage to get out of that.
I do remember really liking Nico: The End, a book written by her keyboard player James Young covering some of that same time period. But maybe its deglamorized portrait of a life in decline particularly appealed to the dumb teenager I was, and it wasn't actually very interesting.