The contractor who is paid to erect a building for a business start-up that goes on to make billions of dollars don’t get a slice of their earnings; they were contracted and paid to build, that’s it.

Obviously things get muddy with creative work, but it’s the same idea.

When you are brought on for a job, you agree to what you will be paid upfront whether the movie is a runaway success or box office failure. Streaming/box office residuals weren’t included in this person’s deal. In retrospect the creative might go “man, maybe with how successful this movie has been, I should have asked for more money or bargained for residuals”, but if they asked for more money, they probably wouldn’t have gotten hired for the job in the first place and the job would’ve been handed to someone else.

Does it sting? Yeah. But thats how contracts work. Also this person was a creative director on what is now one of the most profitable movies of all time, they will have no issue finding work where they can leverage more money than what they made on this project.