Movies are a strange world for actors. You can find there some of the most famous stars were only ever themselves – no matter the part they never changed their mannerisms, their voice or the delivery. Cary Grant a case in point. Some can act in their early movies and then become so iconic for their own presence they never act again. Indeed their best performances are written who their own indelible characters. Jack Nicholson among them. Then there are actors who can hold a stage for two hours and make you believe they are whom they portray and are on cue every take. They are a joy to watch but sadly more and more rare to find.
At least with AI faking it might disappear.