Uh, I went to a top magnet high school and don't remember taking the PSAT, nor many of my peers. Now, many of us took SAT Subject Tests[0], and most of us took at least one AP Test.
As for the SAT, everyone studied their butts off. I also went off the beaten path like the author of the article, and enrolled in a local, inexpensive, SAT study course run by a Korean teacher for mainly Korean-American students in an upstairs office above a takeout restaurant (I was one of the only non-Asian students there). The course involved long hours of drilling vocab and some math, and expected us to drill much more at home.
In the end, the most valuable technique for the SAT was time management. One book[1] even had pages of "answer bubbles" in the back for you to practice penciling your answer, saving precious time. It also recommended skipping/guessing on questions you were having trouble on and moving on to the next one.
Students coming into the SAT with no foreknowledge have no clue that they will be racing the clock. It's not obvious that time management is one of the most important factors and if you simply told someone taking the test cold "make sure you fill in an answer for all the questions" their score would improve by 100 points or more. But I would guess that most students turn in answer sheets with blanks.
As they say, the SAT is a great test of your ability to take the SAT.
[0]: https://en.wikipedia.org/wiki/SAT_Subject_Tests
[1]: https://www.workman.com/products/up-your-score-sat-2018-2019...