movies

Yes, modern movies do occasionally employ oners, but they are usually employed for specific stylistic or narrative reasons. I've not seen 1917, but I have seen Children of Men, which I believe has similar rationale behind the choice, i.e. the characters are in intense, overwhelming, violent and chaotic situations, and the technique is to allow the audience to experience the environment in a way which approximates how the characters are perceiving it. Even if you don't buy my back-of-napkin film theory, you can surely agree that memorable oners from modern movies typically keep the audience's interest by having lots of stuff happen in-frame, managing energy through blocking rather than editing.

Notably, modern oners aren't typically done by rooting the camera in place, and having a mundane scene play out with minimal movement, intrigue, or information being communicated. It's not unheard of, see Zemeckis' Here, or It Follows, but in both cases that decision is informed by the movies' premises. In the case of the latter, it actually wrings tension out of the mundane by using dramatic irony to show things to the audience that the characters are unaware of, and the long takes let you marinate in dread.

However, this is not the case in From Russia with Love. In the scene I mentioned, I don't recall any serious exposition being delivered, or anything of note being shown off by the decision to not cut. Instead you're just watching Bond check into a hotel from the middle of the lobby. Rather it was just the style of the time to let scenes play, regardless of whether or not it was serving the story. In a modern movie, you would accomplish the same thing with an establishing shot of an Aston Martin pulling up to swanky hotel, a cut to Bond and Girl at the counter for perhaps a bit of witty repartee, and then a cut to them in the room. If there's no narrative or stylistic reason for the audience to see the logistics of how characters get from here to there, it's excised.

Like I said, I like em, but it's because these choices make it feel like I'm watching somebody's grandparents' Uber expensive home movie from a vacation they took in the 60s.