Once deepfake tech is so good that we can create hyper-realistic performances at a fraction of the cost (both in terms of effects and salary), the game is really on.
Over time big studios and fans alike will adjust to the idea that a movie doesn't need real actors to be good. Maybe it needs real actors to sell the star system Hollywood has milked since the 20's. But they don't need to be present for filming, and salaries will adjust accordingly.
Many ticket-selling actors will just become celebrity icons and nothing more. You thought the lip-syncing phenomenon of celebrity pop acts during the 80's-00's was bad? Just wait until we are having the conversation about whether an actor can really act or if it's just CG.
In fact, many small studios will survive because of this; like the underground music scene, they will represent "real" cinema with "real" acting. But this will come with massive paycuts and lifestyle adjustments. And higher ticket prices for fans of real cinema.
Underground acting will become what theatre is now: a chance to test your meddle and artistic credibility, at the cost of fame and fortune.
It's crazy that something as artistically extravagant as movie-making scarcely lasted a century, compared to other mediums.
Arrival of a Train at La Ciotat was released in 1896. By 2026 the days of real cinema will be in rapid decline, and if the progress made in the last two decades are any indication, by 2046 it will be all but gone from big studio productions.