"Winning" a debate can have value if there's an audience and where there's something important at stake, but people need to consider that if you get into "debate mode", there's virtually zero chance the other side will consider your viewpoint for a second, so it's a tradeoff with respect to whether convincing an audience matters or having a good conversation where both sides are open to learning something.

I absolutely agree with you that the best conversations tends to come from the latter approach you describe. Unfortunately, it can often be difficult and take some skill to avoid pushing the other person into "debate mode" by making them feel like they're losing. Especially if there's an audience, however small.