To be honest, I had suspicions back in the 2002-to-2004 era....that IQ was decreasing. You could see it with 18-to-20 year old Air Force recruits that I worked around.
What I tend to blame? Poor quality teachers/instructors....high school and college level.
I'd even suggest that 20 to 40-year old 'professionals' are in a marginal IQ 'path'.
It's like some business journalist trying to explain the Biden economics 'idea', and after three minutes....you feel like you are dealing with a 7-year old child.
Is anything going to change? I seriously doubt it.
Even if we were worried about this.....is there anything that could be done at this point? No.