It's not a bad article in Quillette. As he is discussing trends rather than overall scores there is likely something to what he identifies about teaching methods, and the fallacy or attributing scores to recent changes in methods rather than older practices. Yet genetics is not even mentioned as a possibility. It is again invisible.
I'll keep ringing this gong. Nearly everything you have read about education most of your life, including up to the present day, completely neglects the single strongest factor in test scores, our preferred measure of what children have learned. It's the elephant in the room that no one talks about.
Country-wide scores are going to change more as their demographics change than according to any other factor. If professional researchers and experts can't notice the elephant, why do we believe anything else they say?