>IMO, the pressures leading to degradation are all somehow linked to universalization

Liberalism is fundamentally a universalist idea. I mean "liberal" in the original sense: the cultivation of free and indepdendent human beings capable of governing themselves. A democratic society can't survive for long without universal liberal education.

We need to distinguish between education and the education system. You make good points that the system as it is today doesn't scale as much as we might like. But that doesn't mean we should abandon the goal of universal education. Unfortunately, I think the solution requires something much broader and deeper than more schools and more teachers. It requires a culture that values learning and independent thinking, parents who bring up children who are curious and willing to learn, and institutions that uphold these values in society.

We made a lot of progress over the past few centuries, but now there's an increasing number of people who want to question and undermine the core values of liberalism and replace them with something either more elitist, more authoritarian, or both.