This strikes me somewhat similar to saying that we should not use Newtonian mechanics, because we know better that at subatomic level Newton's laws do not apply.
But Newtonian mechanics are still extremely valuable, worth discovering and understanding, and anyone catching a baseball is employing them quite proactively. JTBs are the Newtonian mechanics of epistemology. You can pick them apart at a deeper level and show how they don't really exist, but they are still incredibly useful.
I'm not saying that we should entirely disregard epistemology. After all, belief is necessary to make decisions, and thus to thrive. Although I think people should be mindful that knowledge may not be possible in actuality, just as modern physicists are mindful of relativity and quantum mechanics.
But Newtonian mechanics are still extremely valuable, worth discovering and understanding, and anyone catching a baseball is employing them quite proactively. JTBs are the Newtonian mechanics of epistemology. You can pick them apart at a deeper level and show how they don't really exist, but they are still incredibly useful.