Maybe it's "Authored" vs. "Emergent"

[OldTrees1]

Not all choices a player can make, are good choices. And no, I don't mean they might possibly ruin the narrative. **** it. I'll change the narrative. I'll put scratch marks into my notes and write in the margins. I'm an adult. Take that emergent content and turn it into authored content...Like you're supposed to. There's no problem. Who cares? Doesn't every DM just take players' actions into account? Isn't that just want DMing is?
- A DM starts with authored content.
- The players take emergent actions.
- The DM authors next session with those actions having taken place.
- The players take emergent actions.
- etc.

Again you are misrepresenting the topic. This is a pattern where you are having a different conversation using your own misrepresentation of the topic and then making posts that are by default misconstrued by anyone that makes the natural assumption that you would be talking about the thread's topic.

If I have a setting and I make locations, NPCs, etc, that is not necessarily an "Authored" game. Likewise the PCs being able to take actions does not necessarily mean it is "Emergent" game either. At best I am guessing when I guess you are describing an Authored game that makes minor adjustments to the Authored story based the choices the players made in the last session. It is probably a Linear Branching game but might be a Linear game with details being amended. No, that is not every game. (Although maybe you are using your own unrelated definition and all you described was "The DM prepared, the players played, and repeat. It is really hard to answer your questions when we can't assume you are on topic.)

If I script "the PCs will go to town XYZ to talk to NPC ABC about LMNOP" that is the "Authored game" style as we follow the authored story. If I instead have the players choose what they want to do, and we follow that emerging story, then that is the "Emergent game" style. There are games they will use various mixtures of the two approaches. Although that also means there will be games that appear closer to those two extremes.

So when you said

Which is why to me, most 'Emergent' gameplay is basically the equivalent of 'Can I set fire to it?'

then it comes across as very belittling if we give you the benefit of the doubt and assume you are engaging the same topic.

Consider 2 campaigns in Barovia. In the first campaign the GM titled it "Curse of Strahd" and it is an authored tale of the party having their prophesy told, finding 3 holy relics, and then going to the castle to slay Strahd with plenty of scripted encounters and adventures to flesh out the campaign. In the second campaign the GM started the party in Barovia and followed the emerging story as the PCs decided to revitalize the wine industry in Barovia.

In an Emergent game, the players have enough agency that it is reasonable for the GM to expect to be surprised on occasion. It becomes inefficient to plan every contingency (as the number of possible choices and outcomes increases), thus preparation shifts to being prepared without having to predict rather than taking time to make the bespoke scripted encounters that were efficient in Authored games.