The Mandalorian Luke Skywalker Deepfake

The best results I've seen are analogous to a modern version of rotoscoping. It involves creating a fully animated 3d model of a person and then using a well trained deep fake of the actor's face in combination. Youtuber Shamook did just that with the finale of the Mandalorian season 2. ▶ this video He actually got a job with ILM out of it. The future of CGI actors will probably involve a fusion of techniques like this in order to get it right.

It's a question of cost, knowledge and time. Avatar was in 2009 and the motion capture there was well beyond what was on display in Rogue One. My take on it is that ILM had their own in house animation process and rather than admit that it was costly, slow and gave abysmal results, they doubled down and tried to push it through. Again, there might be some excuses that can be made for Rogue One, but none for Mandolorian and the later Star Wars movies. The Luke Skywalker scene was deepfaked days after the episode aired [0] and, again, the DeepFake version is much better but still horrible because of the animation. [0] ▶ this video

Related: Lucasfilm hired a digital artist, Shamook, who re-did Luke's scene in The Mandalorian with some improved deepfake techniques[1]. Here's his video comparison: ▶ this video [1] link

I don't think you have to watch anything to learn what gives CGI humans away. I don't think anyone has actually managed a truly convincing one yet. This is the closest I've seen: ▶ this video