> What definitely exists in Russia (or at least some big cities) is a system of free after-school classe

I've been studying in a "respected" Soviet / early post-Soviet school.

These classes were super elitist and had a huge disconnect in their level from what you were taught in regular classes.

I was a straight A student and was shut off very quickly. The problems were enormous in their difficulty and teachers had zero interest in helping or educating you.

Those classes were either for 0,1% genius olympiadniks to be later recruited for Soviet science or defense, or for 0,1% elite (Soviet nomenclature) kids whose parents could afford private education.

Along with other naive/poor kids I was quite quickly reminded that I'm not welcome in the circle.

Just a reminder that Soviet system had very entrenched elites and huge discrepancy in access to education, medicine and goods.