Back in my day... we were just leaving the second golden age of Hollywood. Studios were all-powerful, and had stars under contracts that didn't give them much opportunity to choose what kind of films they would appear in. In the mid-1950s, stars started to break away from the rigid studio system and created their own production companies, giving them more control.
Censorship was still a big theme. It started in the 1920s because things were getting out f control as far as subject matter, dialog, and nudity. The studios were afraid the government would step in, so they created their own enforcement system. It lacked teeth, but in 1934 it became a reality. There had been exploitive filmmakers who used language and nudity to attract audiences, but were usually pretty lousy films. Yet there were serious filmmakers who were hampered by some too the restrictions. By the 1960s this system was outdated, and a rating system was created to indicate what kind of audience a film was "safe" for. In 1969, Midnight Cowboy was slapped with an X rating, but won the best picture Oscar, and soon filmmakers were free to create more sophisticated films.
In the late 1920s, film started to replace vaudeville, which had been the predominant entertainment. In those days, a theatre would start the show with music from a piano, organ, or even a full orchestra, depending on the venue. It would be followed by a newsreel (no tv news back then), a cartoon, a serial, one or more short subjects, coming attractions, and the main film. Sometimes there would even be a second feature. This style of presentation would be cut back over time, as television became prominent. Theatres started to shrink; grand palaces seating 4,000 people were common in the old days, now maybe there are a few hundred seats in most theaters.
The major studios each had their own newsreel units to document history run the making, although much of the newsreel would be things like dog shows. Durning WWII, the demand for news was such a priority that many major cities had a theatre that showed only newsreels.,
Today, there is usually nothing more than th main feature and a half hour of coming attractions that lasted many minutes each and usually gave away most of the plot points. And very loud. In the old days, theaters didn't sell food, but now overprice popcorn and junk food are where the profits are. I almost never go to a theatre anymore, especially considering how much more comfortable it is at home with a large screen and good sound. Lots of folks are doing this now.
But no matter how it is presented, film is still a vital artistic medium, even though mostly dumbed down with violent superhero movies.