MIT grad here. The achievement tests are more of a counter-indicator If you score under 700 on either test, you probably cant handle the coursework. The tests only test a 10th grade level.
I likely would not get into MIT this decade this decade with my test score 1480.
Number of stupid mistakes on a test is not indicative of success at MIT. I was lucky in that I test well from having competed in different math contests, but I don't confuse that with being better. If I didn't compete in those, I would have been no less qualified.
The article is spot-on. MIT ignores test scores above some threshold. That's a reasonable way to go.
While acceptance rates have gotten lower, some of it is due to more people applying.
Average scores are higher because more people are studying for exams than 20 years ago.
But I don't think the course work has necessarily gotten any more difficult.
So while it's true that 1480 wouldn't get you in MIT these days, if the same exact "You" were born amongst the kids applying to college these days, your score would likely be higher.
I likely would not get into MIT this decade this decade with my test score 1480.