I think it's multifaceted. Part of it is that English departments, where writers are traditionally trained, have emphasized social activism over classical storytelling. The writers entering into the workforce thus aren't as equipped to write meaningful stories make us think.

Another part of it is that many people don't go to the theatre anymore unless the movie is a visual spectacle. People are content to watch everything else at home. Most of the best cinema I've seen lately have actually been series that were made for streaming from the get-go.