system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does making movie cost so much money?

For example, Endgame’s budget is $356 million. What are the cost of it?

Also for animation movie, for example, Frozen 2’s budget is $150 million. It might sound stupid but I really need to get it out. If the entire movie are made in computer, why is it cost that much?
gpt
It takes a lot of people to make a movie.

Pay attention to the credits and you will see how much people work in the process of making it.

Aside the millions the actors earn, there are other hundreds of people working.

CGI demands expensive hardware and software and there are other production  costs.

They must travel, rent places, etc. 

Marketing costs a lot in order to make a successful movie, and we can't forget the distribution costs.