It’s a (usually bad) way to make an argument; you stand up a false opponent to argument, but because you’re writing both sides they tend to come around.
You’ll see it a lot in “FAQs” put out by, for example, religiously minded folks “Sinners always ask how Boba Fet got out of the Sarlac pit”
(Answer: he didn’t that’s a Disney myth to sell more merch.)