Based on my anecdotal experience, this is the explanation that makes the most sense to me. I've been hearing constantly for at least a decade how atrocious American public education is, which I can't reconcile at all with my experience as a 2010 graduate of McLean High School. Either my experience was so far outside the national norm that I have no useful perspective on this issue, or the national discourse has been totally corrupted by vocal minorities and political agendas.
Personally, my teachers were consistently amazing and brilliant (RIP Mr. Bigger), curricula were rigorous, and I learned a ton that prepared me well for my life and career after high school. Every time I hear about some factoid or perspective that American schools supposedly don't teach because they're propaganda farms designed to churn out uncurious low-skill workers, I roll my eyes as I vividly recall how it was explicitly covered in my classes. It's possible my experience may have been more the exception than the rule, given that most of my classes were advanced/AP/post-AP, but I also had some of my favorite teachers in regular and honors classes and never felt like I was receiving insufficient value for my time. Maybe I just got incredibly lucky, but I really have nothing but good things to say, and can't relate at all to the picture of American public education that's been painted in the media and social media. Granted, a lot can change in 15 years, and my perspective is already going to be skewed by having attended a top-ranked school in a wealthy district.
On the flip side, my public elementary school experience was the polar opposite. In kindergarten I was tutoring third graders who needed help learning to read, but by second grade I'd been kicked out more or less for being bored with the level and pace of the course material. (Effectively. Specifically, the principal was going to move me to special ed unless my mom agreed to find a doctor willing to put me on Ritalin for my nonexistent ADHD. The 90s were wild.) So there's that. Luckily there are some great private schools in the area which my mom was able to make sacrifices to afford, but I can't help but wonder how many other kids weren't as lucky and had their whole life trajectories sabotaged from an early age. Granted, that particular principal was fired a few months after my de facto expulsion (for many very good reasons), so maybe this was all genuinely just an anomaly and very far outside the norm for completely different reasons than my high school experience.