You're not wrong. You can think of internet arguments as a method of developing a thought and collecting counterarguments in a real environment to refine it. The choice of forum affects the quality of the counterargument though, and developing a thought can be done with a crowd more likely to give constructive feedback. If some random website works for you, that's fine.
My statement is more that if you're interested in external impact, exposing someone to a new idea should be treated as the most likely outcome, so assess your effort spent accordingly. I've gotten a lot of value out of reading the different sides of other people's arguments, but I know I personally wouldn't have wanted to spend time being part of it.
My statement is more that if you're interested in external impact, exposing someone to a new idea should be treated as the most likely outcome, so assess your effort spent accordingly. I've gotten a lot of value out of reading the different sides of other people's arguments, but I know I personally wouldn't have wanted to spend time being part of it.