(I upvoted that comment, but:) Truth-seeking is more than avoiding bias, just as typing is more than not hitting the wrong keys and drawing is more than not making your lines crooked when you want them straight.
Someone might have deep insight into human nature; or outstanding skill in finding mathematical proofs; or a mind exceptionally fertile in generating new ideas, some of which turn out to be right; or an encyclopaedic knowledge of certain fields. Any of those would enhance their truth-seeking ability considerably. If they happen not to be particularly good at avoiding bias, that will worsen their truth-seeking ability. But they might still be better overall than someone with exceptional ability to avoid bias but without their particular skills.
Then what the heck do you mean by “equal in truth-seeking ability”?
(I upvoted that comment, but:) Truth-seeking is more than avoiding bias, just as typing is more than not hitting the wrong keys and drawing is more than not making your lines crooked when you want them straight.
Someone might have deep insight into human nature; or outstanding skill in finding mathematical proofs; or a mind exceptionally fertile in generating new ideas, some of which turn out to be right; or an encyclopaedic knowledge of certain fields. Any of those would enhance their truth-seeking ability considerably. If they happen not to be particularly good at avoiding bias, that will worsen their truth-seeking ability. But they might still be better overall than someone with exceptional ability to avoid bias but without their particular skills.