If a movie with famous actor makes 100M more than without them, why shouldn't they get a significant portion of that? Is that DiCaprio number salary, or profit

If a movie with famous actor makes 100M more than without them, why shouldn't they get a significant portion of that? Is that DiCaprio number salary, or profit/revenue sharing as a producer? Looking at [0] it seems like his highest salary was $30M. He made more on Inception and Titanic, but that was total income, not salary. Anyway, when thinking about it as cost and value, then it makes sense in our economic model.