I disagree with this actually.
The main purpose of a movie review is to inform the reader about the film and its ideas. You come to conclusion on your own. they aren't trying to sway you one way or another.
I believe it’s both. They give you their opinion and inform but it’s also to persuade. You either agree or disagree. It’s persuasive writing. If you’re an influencer or a cultural critic, you’re tryibg to push someone in a direction. They’re either with you or they’re not