After over a century of psychometric research in cognitive abilities and intelligence, what do we have to show for it? Whose life has actually improved for the better? Have the benefits from such research, if any, outweighed the amount of harm that has already been caused?
There are studies that empirically measure drop change cognitive ability from lead poising, oxygen deprivation, sleep deprecation, post-burnout, environment distraction, noise pollution, temperature, aging, drug and alcohol use during puberty, smoking, school teaching style, etc. etc.
Notable is that these are either population metrics or compare each individual with themselves. This is what IQ and other similar tests were meant for. Comparing one person with another is nonsensical and a flawed use of these metrics.
This is where where IQ has fallen and become a rather bad metric. People are familiar with the problems scewing results. IQ test performance and education level is highly correlated, which is supposed to be compensated for in the final score. But poor education quality in certain regions make the statistics easily used to argue quite unsavory ideas.
Yes, for the purposes of that research. Why would a comparison between two people be a flawed use case? Do you just mean the colloquial use and understanding of IQ is flawed?
Over two different people, so many factors affect the score that making the claim "one person is more intelligent than the other" is statistically unsound without a massive score difference. This is even ignoring that a full IQ test involves FAR more than the usual online logic puzzles people tend to know, yet still have these flaws.
so yes; > colloquial use and understanding of IQ is flawed.