When you talk to people who’ve crossed over into favoring the home-viewing experience — I mean really favoring it, as in their attitude about going out to a movie theater is now basically Who needs it? — they’ll list the usual catechism of complaints about theaters (the cell phones, the parade of trailers that never ends, the rude bustling inconvenience of it all). But what their conversion to the holy mecca of home viewing really comes down to is the following sentiment: “I’m completely happy watching a movie at home.” That’s a tricky thing to argue with, since on some level we all kind of feel that way. I’ve been watching movies at home, quite happily, since the early 1980s. (If you count The ABC Sunday Night Movie, the early ’70s. If you count the “Godzilla” and “Dracula” and “Planet X” movies I grew up on, the mid-’60s.) I mean, who doesn’t like watching movies at home?

When Warner Bros. made the seismic announcement last week that its entire slate of 2021 releases — 17 films, including “Dune,” “In the Heights,” “The Suicide Squad,” and “The Matrix 4” — would be opening simultaneously in theaters and on HBO Max, you could rationalize it in a lot of ways. You could characterize it as an only-in-the-midst-of-a-pandemic decision — which, in a very real way, it was. You could say it would never have happened were it not for the subscription and branding semi-debacle that HBO Max has turned out to be. The high-octane streaming service yearned to be Warners’ answer to Disney Plus (that is, a must-have for a sizable demographic), but its identity has remained fuzzy (is it boutique or mass?), its numbers unimpressive. And so the announcement of Warners’ unprecedented 2021 blockbuster dump might be considered an ultimate steroid shot in the arm, designed to turn HBO Max into a streaming super-player that could be spoken of in the same breath as Netflix.

That said, whatever the motivations of the Warner executives, by making the shocking decision to go day-and-date with the kinds of movies that would normally be treated as priceless theater-only gems, there’s no denying that the studio shifted the paradigm, creating a concrete glimpse of what the future might look like. They changed the game and, just maybe, opened Pandora’s Box.

That future, as of now, is still unwritten. And it’s quite possible that even “Matrix 4” and “Dune” opening on streaming services will turn out to be a fabulous anomaly. It’s bound to boost HBO Max subscriptions to the max, so many will be crowing about that, and for the I-prefer-movies-at-home crowd it will surely prove to be a popcorn bonanza.

Yet I have some news for them. If they think this is a preview of the future, they are, in all likelihood, sadly mistaken. Why? Because the all-streaming-all-the-time future isn’t going to happen? No, it may well happen. The reason it’s not going to happen the way they think it’s going to happen is that if the movie theater experience, as a cultural force, winds up withering on the vine, then it’s likely that movies as we’ve known them will also wither on the vine. Pauline Kael said it best in the ’70s, when she was writing — witheringly — about the phenomenon of TV-movies. She said that what you make for television isn’t a movie. What you make for television is a TV show.

What the home-viewing disciples don’t want to consider is that when they revel in the virtues of their home movie experience — the comfort! the 70-inch screen! the lack of pesky people making noise! the beer breaks! — they’re having their cake and eating it too. Right now, they’re the supreme beneficiaries of having the best of both worlds: big-scale, swing-for-the-fences movies and the cushy at-home venue in which to experience them. This year, the sense of a brave new world of entertainment in your living room has steadily gathered steam, from the release of “Trolls World Tour” to “The King of Staten Island” to “Greyhound,” not to mention the deluge of exciting independent releases that have opened exclusively on streaming. It will culminate this Christmas with the simultaneous in-theaters-and-on-HBO-Max release of “Wonder Woman 1984” — which became the prototype for Warners’ apple-cart-toppling 2021 master plan.

But imagine, for a moment, that that prototype leads to a new normal. It’s several years down the line, and we’re in the middle of the streaming future. Theaters are becoming a marginal experience (a lure for nostalgic fuddy-duddies like myself), and movies now premiere in the place that most people want to see them: at home! Well, guess what? You’re not going to be seeing movies like “The Matrix 4,” “Dune,” or “Wonder Woman 1984.” I mean, you might be seeing some version of those movies, but it’s not going to be like the version that would have been made for the big screen. It doesn’t need to be — and it wouldn’t justify the budget. Lavishly scaled entertainments like that are based, economically, on a grand scale of viewing (i.e., millions of people around the world paying to see them in theaters). That’s why they cost as much to market as they do to make. You can call that expenditure decadent, but in good movies the money is on the screen. And good movies swing for the fences.

Movies made for the at-home experience swing for…fences that are a lot closer. Besides, in the age of peak TV, when many good series strive, more than they did before, for a cinematic aesthetic, what’s going to distinguish the new made-for-the-small-screen movies from television, except for the running time? You could be cynical and declare that not all that much distinguishes movies now except for the fact that people actually see them in theaters. And, of course, Netflix makes a big show of treating a few of its movies each year — “Mank,” “Da 5 Bloods,” “The Trial of the Chicago 7” — as old-school paragons of extravagant artistry. I don’t begrudge that. The existence of any good movie is to be celebrated.

But what I can’t escape is the suspicion, borne out by the vast majority of Netflix product, that movies made for the small screen have a smaller-scale vision. I say this not to bash Netflix, but because Netflix is already showing us what the future looks like. I say it because it’s like a law of physics. The largeness of movies (popcorn and art and everything in between) is an intrinsic part of what has made them cinema. And great movies have always had a larger-than-life quality. It’s hard to define, but you know it when you see it. You’re going to be seeing it a lot less if it’s streaming only.