>Do you mean, the inability to separate (uncertain, you admit) truth from (likewise uncertain) myth is meaningful, as borne out through a society's technological advancement? This seems like a nod to choosing a truth-position mostly based on its utility...

Sure, yes. That's largely why we care about the truth, after all. We believe operating on truth will result in better outcomes than operating on lies (in general, I'm sure you could come up with specific tortured examples in which that isn't the case). But generally, we care whether X is true because what we should do to get the outcomes we want changes depending on if it is or not. If "easy access to guns leads to more homicides" is true, then banning guns will lower the homicide rate (useful). If it is false, then doing so won't impact the homicide rate while driving up resentment among those affected (the opposite of useful). So knowing whether the statement is true lets us pick the better policy.

And your comment, like OPs, seems to imply a false dichotomy between "certain" and "uncertain". But we have degrees of certainty, and saying something is "true" has only ever meant that we have a high degree of certainty about something, and that is still a meaningful statement.

Basically, just because you can be wrong about what is true doesn't mean that truth should be dismissed as unimportant.