Nobody uses EC2 for this type of workload. The requirements to get any sort of real performance are far too specific.
Dozens of companies exist that have massive render farms and they rent them out to shops working on movies and commercials, but most of the major players have large dedicated in-house infrastructure.
Zync (https://www.zyncrender.com/) was offering this kind of service on AWS but recently acquired it. I think it will get folded into Google Compute Engine somehow.
I think its usage is limited to students and very small shops.
AFAIK they won't even let you spin up anything other than one or two instance sizes they kinda got working. The pricing was ridiculous, $6+/hr if I remember correctly.
Dozens of companies exist that have massive render farms and they rent them out to shops working on movies and commercials, but most of the major players have large dedicated in-house infrastructure.