To be sure, hype about special effects and fancy new technology has always been used to sell movies, an art form that itself started, after all, as a fancy new technology. But the carnival barkers of yore promised us wonders we’d never witnessed before, even if they didn’t always deliver on that promise. Today’s carnival barkers allure us with, well, things we see every day. I’m reminded of all those tech “disrupters” who keep reverse-engineering things that already exist.

To that end, Hollywood has been hard at work trying to create photorealistic fake actors who will be indistinguishable from real performers. “Digital humans are often thought of as the holy grail,” the special-effects journalist Ian Failes told me last year. The industry has been laying the groundwork for this with advances in de-aging and other developments, giving us younger versions of stars who are now middle-aged, old or sometimes even dead. This fall, Will Smith will battle a digitally created, time-traveling younger version of himself in Ang Lee’s “Gemini Man.” The results might be interesting, and the industry will be watching closely.

But even if the film succeeds beyond anyone’s wildest dreams, what will have been proven? And will the movie be that much more emotionally engaging than Rian Johnson’s 2012 hit “Looper,” in which a time-traveling Bruce Willis battled a younger version of himself, who was simply played by another actor, Joseph Gordon-Levitt? Somehow, audiences were able to make the imaginative leap required to accept two very different looking actors as the same person at different stages of his life.

Martin Scorsese’s “The Irishman” will feature Robert De Niro playing a character at multiple points in his life, with de-aging technology used to create a younger version of him. Many of us are understandably excited about De Niro and Scorsese reuniting after nearly 25 years. But it’s also worth remembering that in “The Godfather, Part II” (1974), De Niro himself played a young Vito Corleone, a character made popular by Marlon Brando in “The Godfather” just two years earlier. No computers were required, and somehow, audiences managed to not be confused or bothered by De Niro replacing Brando. One might even say they were enchanted: De Niro won a best supporting actor Oscar for his troubles, and his performance has passed into legend.