The percentage of good movies coming out of Hollywood has always been low. This idea that there was a mythical time when movies were great is nonsense.

The problem is, we tend to only remember the handful of great movies made back when. Nobody recalls the acres of dreck.

The other issue that Hollywood can't recognize a hit in the making was always true. Nobody ever thought Casablanca would be anything other than a throwaway time filler. Star Wars was a completely unanticipated hit, even by the people who made it. Etc.