I can and have taken on entire websites for months at a time. What I mean by this, is that I intentionally go places I know I am not welcome, and post opinions which get me vilified. I have had posts–to be clear, posts that in most contexts would be seen as benign and innocuous–that attracted hundreds of insults.
None of this matters, though. The point is that you can be one single person, and no quantity of contrary opinions can overwhelm a correct idea. The world was not flat when all of humanity believed that it was. Light was still bending even when that was considered impossible.
Thus, I can “debate” 10,000 people, and not be touched, if the views I am defending are the best available on the topic.
You could not take 100 million people of average intelligence, and EVER get the Theories of Relativity, or Newton’s Laws of Motion. There is no quantitative addition that creates quality. It is a different beast. It answers to a different master.
This is why the idea of individualism is so important. We don’t want the average. The average happens naturally. We want the special, and the special disappears in the soup of aggregation.