> I'm not sure people are reading comment chains deeply enough to be swayed by two strangers arguing online
I do, and I have. I’ve also argued something with someone and come out the other side convinced of their position. (Sometimes immediately. More often down the road. Nevertheless, a valuable exchange.)
A very similar experience here. Reading comment threads over the years has absolutely turned me on to perspectives I never even conceived of previously. I've reconsidered my positions (on political and technical matters, mainly) by reading the discourse in comment threads.