It was definitely a thing unions fought for - a big thing actually.
This is the reason why there are so many people missing on movie credits who worked on the VFX - there is no VFX union (there was a huge scheme by some very big name assholes back in the day to block it - and a huge court settlement). Watch any major Marvel or other VFX heavy film and some of the studios will get full credits for their teams while other smaller ones will just list the studio name, the VFX Supervisor (top of the chain) and a few other people. There are tons and tons missing.
This is the reason why there are so many people missing on movie credits who worked on the VFX - there is no VFX union (there was a huge scheme by some very big name assholes back in the day to block it - and a huge court settlement). Watch any major Marvel or other VFX heavy film and some of the studios will get full credits for their teams while other smaller ones will just list the studio name, the VFX Supervisor (top of the chain) and a few other people. There are tons and tons missing.