I believe it exists it's called potatoes or something (real).
Have you tried letterboxd too, I believe that has less censorship than imdb
Discussion
To explain #nostrpotatoes a bit more: It is just a nostr client that creates nostr labels (NIP-32) referring the movie. Any other client could read and display the labels in its own way. Display details about the rating, weight them according to e.g. following status of other reviewers etc.
The previously linked website is just a demo/development deployment demonstrating the concept.
Even if this site is lost, your ratings are not, thanks to the power of Nostr. As long as the relays have the reviews nothing is lost.