Every individual has their own reality. I now wonder if any good comes from contradicting another person's reality. In all the hundreds of debates I have had, I have never once changed a person's mind. To the contrary, I usually strengthen their resolve to hold to their position even when clear evidence in front of us both demonstrates that they are wrong. Often, contradicting another person's reality seems to strain the relationship I have with that person, even when done tactfully. So perhaps I should stop trying. I should let everyone believe what they want to believe and simply seek to understand their reality for my own benefit.
Have you changed your mind through debate? If not, it would hardly be reasonable to expect others to.
When two honest people debate, very rarely do they make a significant change in their position then and there, but it is equally rare for them to walk away without having come to a greater understanding, either of their position, or that of another.
I debate for two reasons. One is to change the minds of others. This has, actually, worked on occasion. Most of the time not, but I've had a number of people concede a point here or there. No one has ever said "Wow, I'm completely wrong!", but you very often plant a seed that germinates through time.
The other reason, and perhaps the more important, is to test my own ideas.
Only through testing them against those wishing to tear them down can your ideas me made more certain, stronger.
And yes, I have, on a number of issues, changed my position as a result of debating with people. It's not even all that uncommon.