In the United States the film and television industry supports around 2.1 million jobs, which equals a total wage paid out as $4 billion. When considering how many jobs there are available in a single film, it is wise to look at Hollywood. In Hollywood the average number of crew credits from 1994 to 2013 was 588. Generally you will have 3 or more writers, 7 producers, 55 or more people in art, 32 plus people in sound, 55 or more in the camera and electrical department, and 156 or more in visual effects. As well as other areas as well.
These numbers are for a live action movie, when it is animated it is different, but for live action movies there are an average 500 people working on a single project. This means that there are many jobs available in this industry, considering that worldwide there has been an average of 2,577 films made per year. This means that each year there are 1,288,500 jobs in the film industry alone across the world. This does not even include television.
Of course, many jobs in the film industry are already taken and there is much competition to get into the film industry. It can be just as hard to get a role in a film crew as it can be to get a casting role, and most of the time you need to start at an entry level position as a runner, even if you have the qualifications for a bigger role.
So while there are actually plenty of jobs available in the film industry, securing one amongst the competition can be quite the challenge.