Film is an ever evolving industry
The cinema industry is heavily influenced by trends and world issues. The most popular genres of any given decade are always influenced by what is going on in the world at that time as well as the number of films that are produced for each genre in that year/decade. For example, during the month of September and October Horror and Thriller movies are very popular and tend to come out often during this period. Similarly In the month of January and February Romance movies take up most of the time slots in theaters. The industry produces movies of specific genres during periods in the year that match the themes. This helps market the films to a more specific audience that is guaranteed to show up to the theater. This is not to say that movies all genres can't be put in theaters anytime during the year but the Film industry has evolved to the point where they can market film and produce them to maximise the success of it not only with good storytelling and filmmaking but also with great marketing and vibe during specific times of the year. The industry has evolved in other ways as well. With the introduction of streaming apps/websites film and TV has grown as an industry. The quality of the content being produced has had its ups and downs with these new changes but film has become a staple of entertainment all around the world.
