Films will never be as interactive as a video game. If you had a star trek holodeck would you still be sitting around watching birth of a nation to measure it's artist merit and impact on the medium of film?
Yes I would, and even though I'm not a huge fan of
The Birth Of A Nation, I still think I'd prefer it to an interactive Star Trek style game.
I think that cinema as an art form will continue to live but it won't be the dominant medium of this century (already I don't think it's the dominant medium like it was in the 20th century). It just seems to make sense to me, did cinema completely outmode painting, sculpture, music (both popular and classical), theater, and literature? No, all of those continued to exist and produce amazing work even though they were not as mainstream as films were.
Video games are an interesting medium but I find them to be too derivative of popular films to create any really interesting art works right now. I think video games should try to really use their unique qualities to create art rather than imitate film through cut scenes and mediocre narratives.
Film will always have unique qualities so it will always last (just as painting, sculpture, theater, literature, music, etc.). Film (and I mean this to include all works of noninteractive moving image such as video and TV) has mise-en-scene, it has the power of editing, it has a special rhythm to it that can be created by the filmmaker, it has the moving camera, it has the underrecognized unique gift of combining staging with composition because unlike theater, film has a fixed perspective to its staging. Film has also produced a countless amount of masterpieces in a variety of genres that can appeal to a ton of different film goers. Right now, in video games there is not nearly as much variety. There's no room for a Yasujiro Ozu, Stan Brahkhage, Steven Spielberg, Tsui Hark, and Satyajit Ray in video games as most of them are dominated by violence or Hollywood style narratives. I feel like video games can serve two functions, it can serve our need for a 'game' like a board game or a puzzle which makes us think about the game and its rules and how we can win. And it can also serve a narrative/artistic function. I think games have done a great job at fulfilling the first function, but the second function needs more artists to create something unique. I think that guys like Yu Suzuki and Fumito Ueda were in the right direction, but unfortunately most video game makers prefer to make less personal projects. Once video games become much cheaper to make, I think it will be interesting to see how it develops. My guess is that it'll be just like cinema, there will be blockbuster games like Call of Duty that are made by big developers, there will be semi-"independent" games which will be bigger but appeal to a more niche audience, and there will be truly independent games which are more personal projects for the game designers. Hopefully there will be great "auteurs" in all forms of video game making. Still, I think that purely as an art form, film will survive and so will all the other art forms. Now I don't know if film will have continued mainstream success.
Oh and if you're just asking about Chaplin let's go a little more recent. Haven't the films of Martin Scorsese, Francis Ford Coppola, and Steven Spielberg left a legacy? So have the films of Frank Capra in the 30's and John Ford's best films and Elia Kazan's method dramas and the film noir genre and countless other films. To go to really recent films, Wong Kar Wai's
In The Mood For Love is pretty much already canonized, the works of Charlie Kaufman are on their way, and I feel that there are quite a few films from the past decade that will be recognized as masterpieces. Cinema has a long large legacy that encompasses a many parts of the world with many great national cinematic traditions. For me, video games are not even close to dethroning cinema as they are almost exclusively produced in the United States/Canada and Japan.
Not to mention, many films are currently being rediscovered and there are many film scholars, historians, and preservationists hard at work trying to bring great works to light and restore the classics we already love to pristine quality. This field is growing more and more every year as cinema is being recognized as the valuable art form that it is by more and more people.