Tangent: It's interesting that the author linked to an article that linked to Sirlin's article about "scrub mentality" rather than linking directly to Sirlin's article.
But I agree with what the author is trying to say: Intelligence is not enough to be successful. No one is going to pay you to "be smart". You have to do something with that intelligence that is worthwhile.
Which is why you have people like Richard Feynman who famously had just "an above average" IQ while contributing greatly to several fields of math and science.
Now, it could be that Feynman just didn't care about the test when he took it. Because he intuitively knew that "being smart" wasn't enough. You had to apply yourself. You have to put in the work and there are no real shortcuts.
Being successful is a multifaceted thing and there are many pitfalls. And the real trick seems to be avoiding as many pitfalls as possible. Being smart helps, but it's not a guarantee.
lordnacho mentioned people think of intelligence as magic, and that's a good way to put it. Every other quality we have as people is not really disputed. If you're taller, we acknowledge it. If you're faster, we can test it. If you're stronger in your arms, we can test it. Etc. And we accept the results. And we accept that if we want to change things, we have to do the work.
But not intelligence. For some reason, no one can be smarter than anyone else. And everyone has to be smart in something. And if you're smart in one thing, you can't be smart in others. We invent things like EQ, street smarts, book smarts, etc to try and put everyone on equal footing. But a lot of times, people who have higher IQs also have higher EQs. And when people talk about "street smarts", what they're really describing is a sort of institutional knowledge that can only be gained by living in an area as often these "street smarts" are highly local to a certain subset of streets. And people often mistake trivia for intelligence. They think knowing a fact makes one smart. It makes one knowledgeable. And often having a lot of knowledge can be beneficial to those with higher intelligence. But high intelligence is often apparent even in those with little knowledge. For instance, my wife is a special education teacher and she has a non-verbal autistic child in her class. He clearly does not have a lot of knowledge, but he's apparently very intelligent. He can work things out. He can make references. He grasps concepts quickly. He gets frustrated by his own inability to articulate his thoughts.