Gen Z dumber than their parents

"Gen Z is the first generation less cognitively capable than their parents.

"...our kids are less cognitively capable than we were at their age. Since we've been standardizing and measuring cognitive development since the late 1800s, every generation has outperformed their parents, and that's exactly what we want. We want sharper kids." 

"Across 80 countries, if you look at the data, once countries adopt digital technology widely in schools, performance goes down significantly. To the point where kids who use computers about five hours per day in school for learning purposes will score over two-thirds of a standard deviation less than kids who rarely or never touch tech at school," Dr. Jared Cooney Horvath reveals.    Source

Two-thirds of a standard deviation in IQ is 10 points. That is the IQ difference between the (historical) United States and Tanzania or Uganda or between Japan and Romania.

Emotion trumps thought

A subject that is very briefly touched upon in the linked article is that the Internet and "algorithms" reward emotional engagement to the extent that it is commonly thought that "feelings", if felt intensely enough, are adequate replacements for math, technical knowledge and...well...intelligence.

"I feel like that wall is thick enough."

"I feel like the concrete has had long enough to cure."

"My steet-smarts tells me that phosphate is used in such small amounts for water-treatment that it really isn't needed." 

I feel sorry for Gen Z. They have been told that they are the very brightest stars to ever have shone in the firmament and that they are the unstoppable vanguard of the future. They believed what their teachers and coaches and academic advisors told them. They really didn't want to hear "old people" telling them "If it sounds too good to be true, somebody is lying to you."