Okay, then imagine you overhear at a bar. Yes “anyone could have” theoretically, but not actually. In either case, you have material non-public information that your counterparty in the market does not.
What if the bar has a cover charge, so only those who pay get in?
What if the cover charge is $10,000 and the bar is advertised as "the place where public company execs love to come talk to each other about private deals"?