If the ideology that produced these books survives to take power, we will have failed as a society. But I'm not worried - we're better positioned than ever to hunt error to the farthest corners of the world, if need be.
Exactly! Children are very vulnerable to unsound ideas - this thread is full of proof of that fact. Allowing them to be exposed to just any content while they're still developing their own perspective is simply inhumane.
We mustn't forget the history that resulted in these racist books. At the same time, it's important to ensure that children aren't exposed to such material.
Removing them from public spaces is a good first step - eventually we'll need to give thought to rummage sales and private libraries (parents often try to pass their erroneous ideas on without the consent of society, of course, and accidents happen).
Given the volume of literature in modern society and the workforce needed to police physical (not just virtual) material, cooperation between all involved interests, public and private, might perhaps be warranted.
(As for "free-speech activists" and so-called pacifists who complain about actions against you-know-who more than violence by them - I don't see the value of their words.)
But better norms are developing, even if it should have happened faster. And not just in technology, but in education and writing and many other spaces.