If you thought we were still a few years away from human actors believably being replaced by digital replicas, we’re actually already there. Check out this behind-the-scenes look at Framestore’s work on Thor: Ragnarok’s visual effects to see how.
In many scenes, Cate Blanchett and Chris Hemsworth’s digital stunt doubles were the ones actually onscreen, although it’s not something to be disappointed about—those CG-generated doppelgangers would have been animated based on each actor’s onset performance.
If it helps, you can think of these visual effect tricks more as digital costumes that aren’t a substitute for an actor’s performance, but an enhancement instead. Except for the Hulk because, to the best of my knowledge, there are no giant Hulks in the SAG union.