It may be wrong in the sense that free will is wrong, but a lack of free will doesn't stop me from making decisions. Causality is all about counterfactuals, and the admission is right there in the name counter-factual. We are already aware.
The most popular framework for causality talks about potential outcomes. If I took my blood pressure meds now (all else equal), what would my blood pressure be at noon? If I skipped my meds today (all else equal), what would my blood pressure be at noon? That tells me the casual effect of the meds on my blood pressure today. But I either will or won't take the meds. One of those branches is simply wrong on a fundamental level, like you say. "What would happen" is in some sense meaningless. But it's sure as shit useful to think about, and that's the whole point.
Said differently, even in a toy model of the universe where everything is deterministic and causality is meaningless on a physics level, causality can be usefully defined on a practical level. Counterfactuals are counter factual, but that's ok.
In a toy model, the ether and Aristotlean mechanics worked ok too. I am not saying we should give up the notion altogether, but that causality as we intuit it may not be the best way to understand the universe.
True. Causation is less useful for fundamental physics than it is for the other sciences. The intent of my comment is that even if causation is nonsensical at the physical level, it may be usefully and sensibly defined at higher other levels. Just like how "true" randomness isn't a prerequisite for usefully defining probability.
The most popular framework for causality talks about potential outcomes. If I took my blood pressure meds now (all else equal), what would my blood pressure be at noon? If I skipped my meds today (all else equal), what would my blood pressure be at noon? That tells me the casual effect of the meds on my blood pressure today. But I either will or won't take the meds. One of those branches is simply wrong on a fundamental level, like you say. "What would happen" is in some sense meaningless. But it's sure as shit useful to think about, and that's the whole point.
Said differently, even in a toy model of the universe where everything is deterministic and causality is meaningless on a physics level, causality can be usefully defined on a practical level. Counterfactuals are counter factual, but that's ok.