Only in Lake Woebegon are all the children above average.
Half the population is by definition below average.
And our current culture is aggressively egalitarian to the point it is for the lowest common denominator. Example - The Learning Channel /TLC moving from science shows to child beauty pageant reality TV. And unlike "I Love Lucy", there is no standard to keep out the raunchy, the sex, the violence. So culture is dumbing down and pulls many down with it, regardless of IQ. When there are no moral absolutes, art degrades to shock value which goes ever further to the extremes, and novelty trumps the enlightened classics.
The interjection of left wing politics into every subject doesn't help, like when they say don't teach Shakespeare or Greek logic because those are dead white men; others say don't teach science because other ethnic groups don't think rationally but "holistically".
I don't think we're down to "let's put crystal healing in chemistry class", but geology journals saying glacier research is sexist and rambling contradictory TED talks on "Islam is wonderful, ask my mother who has to wear a hijab" says we're close.