Popper would have been better off saying that he was advising us on the search for precision and parsimony, by making truthful statements along the way, rather than coopting the word ‘truth’ from his spiritual background. We are not investigating the mind of god. Nothing is obscured from us. Nature doesn’t try to lie to us, nor is nature mistaken.
The question is not ‘is that true’ but ‘can I testify to and warranty this?”
Linguistic blame avoidance caused a lot of ripple effects in philosophy.
But popper’s culture was not one of truth telling (as his own rhetorical attacks on competitors evidences.) Cosmopolitans are pragmatists not truth tellers. They do not warranty their speech as do westerners.
Meaning in cosmopolitanism is utilitarian and escapable, not truthful and warrantied.
Popper relies upon cosmopolitan truth (the unknowable mind of god), and cosmopolitan truthfulness (non-warrantied speech).
This is why he could advance science but that was the limit of his solution.