If a player declare their character climb a cliff, and resolution indicate they succeed on this task, then indeed the character will (presumably) find themselves at the top of the cliff. However this is due to the in-fiction causality link between the act of climbing and the change of position. There happen to be a correlation between hope and what happened to the character, but there are no direct causal link. (The causal link you might find is that this hope was what motivated you as a player to declare that action)
In the fiction it seems to me that there is a causal link, in that but for the hope of getting to the top the character wouldn't have attempted the climb.
And as you note, there is an obvious causal link, at the table, between the player's hope that their PC gets to the top, and the narration of their PC being at the top: the player has their hope for their PC, the dice are rolled for the climb check, the roll succeeds, and so everyone agrees that the PC is at the top of the cliff.
In my example of the strange runes in the dungeon, there is a causal link in the fiction between the PC's hope that the runes will reveal a way out of the dungeon, and the PC's choice to try and decipher the runes, which results in the PC learning that the runes do, indeed, reveal a way out of the dungeon. The PC, of course,
does not cause the runes to say what they say; but the PC, by reading them,
does cause it to be the case that he knows what they say.
Turning to the table: there is a causal link between the player's hope that their PC will find a way out of the dungeon by reading the runs, and the narration of that happening. It is the player's successful action that causes everyone to agree that the runes reveal a way out, but
not because the player directly authors that fact: rather, the player's successful action declaration establishes that
the PC learns the way out by reading the runes, and this entails that the runes reveal a way out.
This is a special case of the general point I made upthread: in the fiction, the metaphysical truth about the runes is what causes the PC, by successfully reading them, to have a true belief about what they say; but at the table, it is the agreement among all of us that
the PC has read some runes that reveal the way out that then makes it true (by entailment) that, in the fiction, the runes say what they do.
So the key question is
what action declarations are permissible and
how are they to be resolved? An alternative way of resolving the declared action
I try and decipher the runes to see if they reveal a way out of the dungeon is (i) for someone to decide what the runes say independent of the resolution of the declared action, and then (ii) use that decision to help establish the result of the declared action - in particular, if (by whatever means, eg a knowledge check) it is determined that the PC can read the runes, the decision as to what they say is then drawn on to tell the player what it is that the PC reads. This is the process that I used in the Torchbearer 2e episode of play that I posted upthread.
These are different processes both for resolving the action declaration, and for establishing what the runes say.
I find myself being grilled on if the difference I expressed really exist. It make no sense to me that you would deny the existence of a difference, and hence it is comforting that you acknowledge that there are some difference in your second paragraph here. I have made another attempt at expressing even more presicely the difference between the ways of playing, but I am really not sure if this is a wortwhile project.
Whether it's worthwhile is, I guess, a matter of opinion.
I think that most attempts to explain what is going on fail to take seriously how fiction is established, and to pay close attention to the details of how action resolution works. I've tried to set these out in details just above, as well as in other recent posts..
I initially try to express how the thing that is widely advertised as a strength of these techniques can have detrimental effects if used in inaproperiate context. That these techniques shouldn't be used in inaproperiate contexts appear from previous things you have written is something you would completely agree with. I actually would expect you to agree to the notion I attempted to express, or maybe point out how I am unpresice about what context might be inaproperiate.
<snip>
At least at the current stage I think it might not be relevant to express exactly what the difference is as long as we can agree that there is a difference, and that this difference grants players more formal power over the narrative than trad. I think this fluffy premisse is enough to arrive at the conclusion that this difference cases distruption to a play style caracterised by player influence matching what they have in trad.
Indeed expressed like this the central claim actually seem to reduce to something close to a tautology..
Well, it does seem tautologous, or close to, that doing something inappropriate may have detrimental effects.
My interest is in achieving clarity about how different approaches to RPGing work. As I've posted upthread, trying to do this by looking at characteristics of the fiction, rather than of the play process, is in my view hopeless.