I guess you could say that DW (and AW) use "say yes" but it's so far baked into the game that the GM shouldn't be thinking about it. If a move comes up that means there's something at stake.
Take Perilous Journey for example. We could have said "here's the system for journeys, use it when there's something at stake on a journey." That's say yes or roll the dice. Instead we have a trigger "When you undertake a perilous journey..." This way instead of the GM thinking about "should I just say yes? Is this a conflict?" the GM looks to the fiction established: "is this journey perilous?"
...The hard work of figuring out when to say yes is already baked into the game.
Well said! The conditions for the Move must be clearly met for the Move to work well and not require double-checking, as you said. If I attack an opponent in melee, then by god I am Hacking and Slashing! Volley is equally concrete, and Defend is pretty clear.
Defy Danger is broad ("act despite an imminent threat, or suffer a calamity"), but the different options for each stat give us much narrower fictional cues. It's more interesting than its direct ancestor, Act Under Fire (the most-used move in my AW games, omg), and it reinforces niche protection. It's really colorful and rad!
The problem I run into is that I can't picture what Spouting Lore is really doing. Is your character standing there talking aloud? - - that's how I interpret it when someone Aids another on a Spout Lore check: they have a conversation.
But whaddya do if you roll a 6 or less when you Spout Lore, or Discern Realities? You have to make up your own answer, more or less, and this is also how I felt about Open Your Brain from AW.
It's like Say Yes is baked like apples into pie when it comes to most Moves, but the information-related moves (in AW and DW, that is) feel a bit more raw and uncooked - they stand out from the rest of the "pie" of play that much more in that they require longer pauses while the GM thinks up a reasonable answer.