This way they can give a young CGI Leia her own prequel.
I think acting may become somewhat obsolete. You could see it in the LOTR movies where Gollum was an important character, but only shown as CGI.
Humans will do voices (though perhaps not for long).
Humans will wear movement tracking devices so that the computer can capture them.
But the look of the characters will more and more come from a computer. And some beautiful, seductive “actress” may have a starring role for many, many decades. Why not? It’s cheaper and the public likes to pretend that people don’t age.