Or alternatively it empowers the players to make impactful decisions with real meaning as the fictional reality their characters inhabit is not an amorphous mutable mess.
No one's game fiction is an "amorphous mutable mess" as best I'm aware of. And the players in the games I GM make impactful decisions with real meaning - eg to kill Gerda, to kill Megloss, to seek the help of the Void cult, to reach a deal with Lareth the Beautiful, etc.
You seem to be assuming that there is a more-or-less strict correlation between an absence of resolution by causal extrapolation, and an absence of concrete fiction elements and relationships at stake in a given scene. That assumption is not correct.
And if you're not making that assumption, then there is even less basis for thinking that you have identified a distinct virtue of the causal-adjudication approach to play. It's virtue is not
meaning. It's virtue is something in the neighbourhood of
puzzle solving - analogously to identifying the hidden pieces on a gameboard.
In Blades you don't need to make concrete plans for your actions, but you also really cannot make concrete plans as there is no concrete reality to begin with.
I can't comment much on planning in BitD, which I've not played - although I do know that there is such a thing as gathering information, which looks to me like a type of planning.
But I don't really see the connection between (say) the sort of planning that Gygax describes in his PHB (equipment and spell load-out, a "plan of attack" for the dungeon level, etc); or the sort of planning that might figure in a Shadowrun or certain sorts of Traveller or even Cthulhu scenarios; and "impactful decisions with real meaning".
I've GMed sessions of Rolemaster where a lot of time has been spent by the players optimising the use of spell power points to prepare for a particular mission their PCs are about to undertake. There's a type of pleasure there, somewhat comparable to the pleasure in solving a sudoku or crossword - but it's not about
meaningfulness.
And I've played RPGs - investigative scenarios in various systems - where a good chunk of play is about ascertaining the "true" state of the fictional situation, by unearthing the hidden information without doing anything so flagrant that it upsets the whole applecart (in virtue of the GM's causal extrapolations). Again, there can be a type of pleasure there, but it's not about
meaningfulness either.