The point is that costs are fixed, but revenues are not. They don't make a product and sell it once with a win. Of course you could argue that they have a business risk and all that, but at the end of the day, you'll have to work for every extra dollar you make and they don't.
I love it when I'm being paid by the day because actual money ends up in my pocket. I have ownership interests in a number of films and the only reason I hold onto the contracts is sentimental value - none of them will ever make any money.
Only about 20% of films break even, and only a very small number of those make long-term royalty income - and that was true before the internet upended distribution models - which is why the careers of studio executives are so precarious. For indie producers, creatives, and technicians it's almost all business risk. Most projects don't pay very well (if they pay at all) and never recoup their production costs. At the indie end your goal is to win some prizes and get a film into distribution, and maybe make some of your money back if you put money into it. The win condition is that having distribution shows you can make work to commercial standard and maybe someone will like what you've done and give you a larger budget to work with.
To break even typically requires a film to spend about the same money on marketing as production costs, and of course films compete mainly against other films that are released around the same time. Unless you are exceptionally lucky and talented, there is little chance that you will make money with a production budget under $1 million. The typical 'low budget indie movie' that most people think of - quirky romance or gritty crime story - costs $5-10m.
Those are pretty high barriers to entry. It used to be that you could bootstrap yourself by doing some straight-to-video films that were not necessarily very good but were sufficiently adequate to find a small audience in between good big-budget movies, eg James Cameron's first directing job was on the Piranha 2 which was every bit as bad as the title suggests. But now that you can stream many movies you'd want to watch or download a high-quality movie if you're not happy with the streaming offerings, the fims with very small budgets are competing head-to-head with larger-budget offerings and of course the large-budget offerings win for all but the most devoted cinephiles and genre fans, of whom there are not that many.
Most people in the film industry never see any residual income worth talking about. And when they do, residuals are basically compensation for the fact that there are few regular paychecks to be had. You know the best way to make money in film? Run a food catering business. Regardless of the budget, it's an iron rule that production pays for the food and everyone gets at least one square meal a day. For short films and micro-budget projects, food is often the single biggest expense.
It's incredibly challenging to make a profit on a genuinely independent feature these days - close to impossible, in fact.
And whilst YouTube apparently offers a new hope for video, the fact is it's its own creature, and really doesn't support drama - or anything that takes more than five times as long to make as to watch - terribly well.
Oh, lastly - sound recordist also works pretty well as a paid gig in film, apparently. It's hard to get a guy to hold a boom mic for 12 hours for free. But other than that, making cash in film is... tricky.
I'm really good at it and I don't work for free, but I am always being asked to, which is how I come to have an ownership interest in some films, I'll take a percentage depending on who's involved. The sad reality (and this is true for camera and lighting people as well) is that very often you're being offered/paid rental for your equipment and nothing for your work.
