Is it true though? There's plenty of evidence that IQ test performance can be learned (i.e. you score higher) with prior training. That's why it's often insisted that tests be taken "out of the blue" without any preparation whatsoever.

Taleb doesn't mean IQ doesn't test something real. He says this "something real" is irrelevant.

I was in the US military, and they used something called an ASVAB test to check your suitability for various jobs. It's one of the few skills tests I've encountered that seemed both reasonably accurate and useful.

I'd much rather see the results of that for a potential job hire than I would want to see their SAT scores, IQ, etc.

The ASVAB effectively is an IQ test. There's more of a breakdown than other tests, but you can calculate IQ from it.

The SAT isn't considered a proper IQ test.

Surely I am dating myself, but pre 1994 SAT tests were said to be better.

Total SAT (math and verbal scores), divided by 10,were supposed to be close to the measured iq.

FWIW my SAT divided by 10 was within two points of my mother's IQ testing from decades before.

The breakdown is what was useful. Mechanical aptitude separate from other concepts, for example.