It's more a case of the box office becoming less and less a factor in determining a movie's "legs"

A cult film is something that didn't get a lot of traction at the box office and later did, via the secondary viewership audience. Which was the only way we could track a movie's popularity. Now that streaming has taken over, that's all changed. No one's rushing to see movies when they can take their sweet time, and these same people will often refuse to see a movie if they feel they're being pressured