To stick my nose in where it doesnt belong, if you can't articulate what you think and believe, you don't really understand it. So, talking to people is a way to give them a chance to change your own mind more so than to change theirs, and if they can't do that, to give yourself an opportunity to understand your own view better and even change your mind when you arrive at an even more clear understanding.
Attempting to change the mind of an entrenched ideologue is a difficult thing. It is likely to fail. If anything, passers by less invested in any point might be interested in understanding your view, even if they don't come to the same conclusion, that's more valuable than changing the mind of the person you're having a conversation with. But you must always enter them in good faith regardless, willing to change your mind, and expecting that the other is willing to do the same, at least until you see evidence of disingenuousness in them.