By a plot, I mean a structural one. None of the ones you mentioned except for the last two had plots. The studio is famous for going on record saying they go out of their way to make their movies scriptless, instead preferring pure improv, though it kind of shows in how freeform and non-rule-based it feels. To be fair though, it does help to have read the book it was based on, you get the context of where exactly the movie begins to lose its identity (and appreciate it was trying to have one).