I think the simpler answer (and thus more likely) is that statistics education in the US is very bad (they should teach stats in high school, not calculus), and reporters just don't understand it. And the ones who do, believe (correctly) that their audience does not understand it.
That's exactly why they use averages, though. Propaganda is insidious in that way.
I think the simpler answer (and thus more likely) is that statistics education in the US is very bad (they should teach stats in high school, not calculus), and reporters just don't understand it. And the ones who do, believe (correctly) that their audience does not understand it.
Who is “they”? I believe open AI would share averages for that reason but not that media would choose to cover it that way.