I'm going to go out on a limb and say movie theaters won't go away.
Drive-ins are a little different for two reasons. First, they take up a large chunk of real estate--there's no such thing as a small drive-in. Movie theaters are a little more scalable. Second, depending on the car, sitting in it for extended periods isn't always as comfortable as a good theater would be.
Theaters are convenient in some scenarios, particularly if you're working on a modest budget. I'm thinking especially of people seeing a movie together, particularly in a large group. If you've got a house with a large enough room, a wide-screen TV, and a great sound system, the experience might actually be better than in a theater. But if you're living in a small apartment with a not-exactly-state-of-the-art TV, the experience might be better in the theater, certainly for a large group. And even as expensive as tickets are these days, the occasional in-theater experience may still be cheaper than upgrading the home entertainment system.
Sometimes, it's also nice to just get out of the house. Movies are a good excuse to do that and can often be combined with dinner. (And for adolescents, it can be a good opportunity for some physical contact without either set of parents leaning over your shoulder.)
It's clear some theaters are a adapting themselves into a luxury viewing experience. There's probably also room for theaters at the other end of the spectrum. We forget that movie theaters initially catered to a broad audience, including low-income people. That's still a large group that probably doesn't have state-of-the-art equipment at home, and, with the demise of TV antennas and free broadcast programming, not everyone has a great cable package or decent streaming internet. If a theater chain could find a way to offer movie viewing more economically, there'd probably be an audience for it. During the Depression, when my parents were growing up, movie theaters changed programs three or four times a week, and a very cheap ticket included two movies and one or more shorts.
OK, so maybe I'm dreaming on that last part, but I believe the other arguments are sound.