The look is likely a combination of subject, optics, film/print texture, and tonal treatment—not one single factor. From the community answers, the main contributors are:

• soft lens rendering or slight softness overall
• dunes with very little mid-size texture, which makes tones blend smoothly
• film grain adding a false texture over otherwise smooth sand
• strong black-and-white contrast and darkroom-style printing choices
• the scene and lighting itself, which are crucial

A similar result can be created digitally. One answer suggests a simple approach: convert to black and white, add a bit of blur/softness, then add gaussian noise or grain. With careful tonal adjustments, you can get closer still.

So no, this look is not exclusive to film. Film grain and darkroom printing can help, but the “brushed” quality also depends heavily on photographing the right subject under the right light, then using restrained softness and grain in post.