Or anyone making music, or editing video. The commercial offerings in those areas still far outstrip anything available on Linux.
But a lot of the Linux machines you see in VFX shops are just headless render nodes. People doing the creative work often use Macs or PCs.
You'd have to get their Mac (or sometimes Windows) machine out of the special effects guys cold, dead, fingers.
That said, there are a few commercial offerings for 3D modeling work on Linux, but shockingly less than in Windows/Mac land.