I have never had a hotel find anything that was left behind, even when I described exactly what it was and where it was. Sometimes, it is even of dubious value (e.g. a worn dress shirt). Usually I call the same day or immediately the next morning after checking out.

Usually I get a run-around and they'll "file a report". My guess is that usually it is thrown away or kept by housekeeping. "Filing a report" probably never happens.