I have some personal experience with this. I actually owe my online writing career in a way to work I did debunking the Flat Earth conspiracy theory.

Back in 2016 or so, my business partner's brother told us he'd done a lot of research online and had become convinced the earth was flat. He was anxious to show us his amazing discovery, which meant he was anxious that we watch several flat-earth YouTube videos.

Well, we did, and the videos were slickly produced and contained some truthful data , but presented in such a way as to lead to false conclusions.

My business partner wanted me to show him why the videos were wrong, so I sat down with him and took him step by step through through mathematics, mostly geometry, that's been fairly well known since the time of the pre-Socratics.

He was convinced and brought his brother in for the same tutorial. His brother followed along and agreed with every word I said, but added, "I still believe the Earth is flat. What you say looks convincing, but those guys on YouTube look convincing too. I believe them."

So ... my partner and I conducted a series of experiments with his brother. We used photography to measure the rate at which ship superstructures sank below the horizon. We bought a sextant and a telescope and with the help of a similarly equipped friend several time zones away measured the distance from the earth to the moon. We got an answer that indicated flat-earth theories had to be wrong.

We did not replicate the famous ancient experiment to discover the circumference of the earth, because it was the wrong time of the year. But we were prepared to.

His brother helped us with each experiment and followed closely as I worked out the math on paper, line by line until he understood each step.

This process took about 3 months. At the end of that time his answer had not changed. He told me I was very convincing, but the YouTube guys were just as convincing, and he preferred to believe them.

During those three months I shared a lot of my findings online where flat Earth people were announcing their "amazing" flat Earth discoveries. I was sure that once they saw real observations with real data with math that really worked, they would have to change their minds.

Guess how many flat Earth people told me I had convinced them? Zero. Not one.

I put months of effort into debunking an obvious falsehood and got pretty much nothing in return. I really felt like I had wasted my time.

On the other hand, going online to engage with flat Earth communities got me writing on the Quora social media platform. I found a cool community there and made some friends and soon began writing about other things than flat Earth. Before long I was mostly writing about HIV/AIDS with an emphasis on treatment and prevention. Then I branched out into more general LGBTQ writing.

Then I moved to Medium, and here we are.