This article was kind of weak sauce, in my opinion.

It’s true that students in Finland, South Korea and Canada score better on mathematics tests. But it’s their perseverance, not their classroom algebra, that fits them for demanding jobs.

The author drops this in about halfway through, and then provides no citation to back up the assertion. It kind of reads "They're not lazy like we Americans are!"

There may be a compelling argument about how math and algebra is taught in schools, or what is emphasized. The author seems to agree when he says

What is needed is not textbook formulas but greater understanding of where various numbers come from, and what they actually convey.

I'd respond that it's both- the formulas are meaningless without understanding of what they mean, but that doesn't mean that the formulas themselves are entirely meaningless.

But there’s no evidence that being able to prove (x² + y²)² = (x² - y²)² + (2xy)² leads to more credible political opinions or social analysis.

And there's no evidence that taking philosophy made me a better engineer. That doesn't mean that it was a waste. I'd rather be well-rounded than pig-ignorant.