One potential difference is that the input data required to render a single frame of a high end animated or VFX movie might be several hundred gigabytes (even terabytes for heavy water simulations or hair) - caches, textures, geometry, animation & simulation data, scene description. Often times a VFX centric cloud provider will have some robust system in place for uploading and caching out data across the many nodes that need it. (https://www.microsoft.com/en-us/avere)

And GPU rendering has been gaining momentum over the past few years, but the biggest bottleneck until recently was availabe VRAM. Big budget VFX scenes can often take 40-120 GB of memory to keep everything accessible during the raytrace process, and unless a renderer supports out-of-core memory access, then the speed up you may have gained from the GPU gets thrown out the window from swapping data