I think in D&D the DM decides how much they care about pacing.
I think in a game where the players or the dice control more than a little of the pacing, the GM can't really care about the pacing, because they have so little control of it. A carefully paced fragment will ... clash (like plaid with plaid) with the rest of the game.
When I GM 5e, I tend to let the players kind of dictate the pacing, but if things begin to lag for some reason, I look at it as my job to get things moving again.
The group of peopleI play 5e with have a lot in common when it comes to how they play, but there are also some differences. So there may be a time where one player expects for a scene to be played out, while other players are fine if it’s just narrated and we move on. I have to find the balance where the one player’s desire to play things out is met, but not at the cost of the other players’ attention.
So I definitely get involved in the pacing, but I wouldn’t say I control it.
With other games, it can really vary.
@Ovinomancer says he’s not worried about the pacing when he GMs Blades in the Dark, and I get why, but I’d say my rake is a bit different. I am concerned with pacing in that I want to make sure each phase of play has sufficient time. To me, this pacing is more about logistics of the time we have than it is about building drama and the like. More practical than dramatic, I suppose.
To bring this back to play stalling, I think D&D is more prone to this because of the way the game works. The GMs notes/module/adventure is there and there are ways in which it can/should/may be interacted with, and sometimes the players lose track of that, or can’t figure it out. The same isn’t true for Blades because the players have chosen the Score, what kind of plan they’re executing, and the detail of how that plan connects to the Score. They can’t really lose track of that.
Aside: I think this is a big part of the obstacle when discussing and comparing different games. We take an example from one game (like
@Manbearcat ’s lake/kraken scene for 4e) and we try to transplant that scene to another game. But that often fails because the games function so differently that the entire scene/encounter would need to be redesigned entirely.
It seems to me somewhat like an adaptation from one media to another. Taking a scene from a book and trying to portray it on film probably can’t be done perfectly. You’re going to have to make changes to suit the new medium.