What do you think of using modern technology to make biopics more believable?
For example, with the movie Walk the Line (2005), "deepfake" technology could be used to make Joaquin Phoenix look like Johnny Cash, and there's also technology that could be used to make him sound like Johnny Cash too. Even amateur YouTubers can do this now, for example, "Johnny Cash" singing Barbie Girl:
https://youtu.be/MAFdzBTe2lg
It's practically indistinguishable from the real Johnny Cash's voice; certainly far more convincing than Phoenix's impression of it.
Hollywood could do it even better than YouTubers can, both the voice replacement and the face replacement.