Assuming others might know something I don’t, and being open to learning from them, makes perfect sense; I don’t know everything about anything, so I can potentially learn something from everyone I meet.
But there are certain people with whom I should avoid engaging in prolonged or repeated discussions, those who fail to think in a certain way. Paul refers to perverse disputings of men of corrupt minds, and exhorts us to withdraw from such folk. (1Ti 6:3-5)
Evidently, there’s a certain kind of attitude in debate that’s perverted, unhealthy, irrational, twisting and corrupting the purpose of debate. When a person isn’t thinking clearly, having lied to themselves so often that they’ve seared their own conscience (1Ti 4:2), there isn’t any way to reach them with facts and evidence, so we must have some other purpose in engaging them in conversation, or we’ll be be frustrated and irritated. (Pr 29:9)
There’s a difference between being ignorant, and being self-deceived. I tend to make the mistake of thinking that if people just have enough evidence then they’ll change their minds. The longer I live, the more I think this is a rarity. Most people aren’t open to learning and changing their minds about anything; they’re just in the debate to exalt themselves by putting others in the wrong, but this isn’t the purpose of debate.
Healthy debate can only occur between two people who are both seeking truth, and it’s extremely beneficial, iron sharpening iron. Outside that unique context, we need to set expectations reasonably, and persist only to improve our own understanding, enhancing our own ability to give an answer to him who asks sincerely (1Pe 3:15), not expecting to help those who aren’t.