Школьное образование – это процесс, который научил огромную массу людей читать, но научить их правильно выбирать, что читать, он не смог.

English Translation

Schooling is a process that taught a vast crowd of people to read but wasn’t able to teach them to decide what is worth reading.

Schooling is a process that taught a vast crowd of people to read but wasn’t able to teach them to decide what is worth reading.
Maybe “has taught… hasn’t been able to” would be a better translation?