You can do very much with very little when you force yourself to be constrained. Of course that doesn't mean everything works without dialogue, but many things are different in ways that may sometimes be better.

Watch City Lights, by Chaplin, for example. One of the last great silent movies. You can argue it could have been funnier with more dialogue (it has some in the form of intertitles). Maybe it would. But it wouldn't have been made that way with more dialogue. Many of the scenes are structured the way they are because dialogue isn't there as an easy out of situations, and forced Chaplin to think long and hard about how to show instead of having characters tell. I'm sure the same story can be done well with talking characters, but it's not a given at all it'd have been better, because the script would almost certainly have been very different.

The most famous example from City Lights is probably the scene where Chaplin gets mistaken for a rich man by a blind girl selling flowers, which is a major setup for the rest of the movie.

Chaplin struggled with it for ages, because he felt he needed to actually give a reason to explain why she'd think he was rich.

The solution is beautifully simple: Chaplin steps through a car to avoid a police officer, and slams the door, both signalling his presence to the girl and signalling initial wealth (the movie was filmed in 1928/9). We (and he) learns that she is blind by seeing her not realize he's picked up the flower (there's one line of text there), he pays her, and as he has just handed her effectively the last money he has, the owner of the car enters and the car drives off, leaving the girl to think Chaplin did not wait for his change, giving her further reason to assume his wealth (there's another intertitle with one line there).

It took weeks of filming over several periods to get it right; both because Chaplin struggled with finding the right mechanism, as well as because he insisted on showing her blindness realistically (and so he rejected a whole slew of actresses he didn't believe could realistically portray being blind). With dialogue it'd be so easy to cop out and use some dialogue to cause the confusion.

As it stands City Light is frequently considered one of the best movies of all time.

The scene in question is here: https://www.youtube.com/watch?v=hCPGFTp0vmo

That scene is emotionally moving in a way that isn't done today. Thank you for posting that link and your explanation.

Think bigger! One of the best episodes of Buffy the Vampire Slayer was almost entirely silent, and yet still featured the cleverness the show is known for. Some of the most evocative scenes in recent movies are largely dialog-free, such as several scenes in Roma, or Gravity. It isn't just Cuaron, either, remember Castaway?

Imagine a movie that can be watched with no sound but still tells the whole story. Now imagine the same movie can be listened to without seeing the screen, and again, tells the whole story.

The point of "show, don't tell," is to keep lazy or beginning writers from relying too heavily on assumptions about their readers. It doesn't mean "make things explode and don't worry about the plot making sense."

Dialogue has its place, in certain films. Those films would be what they are without it. But even in those films, there are usually parts that are without dialogue and those parts would arguably be worse were they filled with dialogue instead.

Many of the most emotional and powerful parts of great movies are shown, not told. Also, I'd argue that it's usually worse and more shallow movies where every little bit is explained and spelled out for the viewer (often in dialogue or narrative exposition), and very little is left if anything is left for them to figure out, make sense of, or decide on their own.

Petty gibes aside, Michael Bay is a good example of what I'm talking about. You can listen to his movies without watching and understand, more or less, what's going on because the characters explain everything they're doing. His movies would be better if he only showed explosions and opted out of dialogue explaining what the explosion meaans to the plot.

How dare you insinuate... Of course I picked Michael Bay on purpose for exactly this reason. His characters frequently devolve into expository prose that’s quite superfluous.. to adults. Kids on the other hand really appreciate the characters telling them what they’re about to do. He’s just catering to the audience. What’s annoying for us is essential for them to follow the plot.

“Show don't tell” doesn't mean avoid dialogue, though it does imply (in filmmaking) avoiding gap filling by omniscient voice-over narration. It also means minimizing exposition in favor of demonstration, but much dialogue in film is demonstration, not exposition.