You seem very certain. Several of the links in that wall o' text are merely to surveys where a number of psychologists are asked whether they think IQ is a valid measure or not.

The reddit post just shows that some (maybe even a majority of) psychologists accept IQ. I could post an equal amount of links to psychology studies rejecting it. But that doesn't even matter. What's more important is that the field of psychology as a whole is still in it's infancy as a science. Up until about the 90's almost 100% of it was pure bunk. Psychologists were using the DSM up until only a couple of years ago! Recently there has been the revelation of the reproducibility crisis. In short, psychology has a long way to go before it's on the same level as other sciences, I wouldn't be so certain of something from psychology's dark past like IQ.