And games! Games do too. It's because it's a huge collaboration- without everyone listed, the final product would be different to what it is you're watching/playing etc.

Anyway, that's not the answer you're looking for, but as a game developer and artist, I just wanted to add that it happens with games too, and it happens because of this :)

It's an agreement with their union, IATSE.

As this is not a question about history, it has been removed.