I think it’s debateable.
I think it depends on how its measured and what they are measuring.
Dropout rates are very high in urban areas. We’ve got people who can’t spell their own names or make proper change for a dollar. We hear of the plight so many kids going to college have to take remedial courses just to get up to par to be at college. They are not ready to take the basic entry college courses. We’ve got experts in fields that are worthless.
Further 100 years ago a lot more people knew how to take care of themselves in extreme conditions. They could survive. Try that with most of us today.
IQ is not a guarantee of intelligence. Look at the Harvard knobs. There are experts in certain fields that are clueless in other areas of life. Or very smart people making very bad decisions despite their intelligence.
If that's true, then I could go to the physics, math, and science departments of many universities and find professors with sub-100 IQs. Ditto for going to firms that work with physics/science-based problems and find the people involved with low IQs. I bet I couldn't. I bet all the geeks in Silicon valley who work in the computer industry have on average very high IQs. I bet all the people deeply involved with the Manhattan project had exceptionally high IQs.
Having a high IQ does not mean a person will be a success in life. But it does denote high intelligence of a sort. And even if smart people occasionally do stupid things (which they do frequently), that does not invalidate the fact that having a high IQ is a much better predictor of success in high intelligence-based enterprises than average or low IQs.