Movies, however, typically do add plot when adapting plotless materials. It’s not inherently a problem that this movie doesn’t, but it makes zero effort to consider that what works onstage may not work onscreen.

It's actually worse than that, because they dif add plot: None of the Macavity as villain stuff is in the play. It's just a bunch of set pieces about cats and then Grizabella ascends to the Heaviside Layer.