supposedly because USSR didn't care much about most of the students, they wrote hardcore books such that a talented student in a remote village will get the knowledge and contribute to building rockets in the future. No one cared for the remaining 99.9 percent of students and their pointless struggles

I went through eastern block's educational system (elementary and high school), the revolution caught me as I started university, I do have personal experience.

Three factors were at play: 1)Not much dumbing down, if you don't get it, you will barely scrape through. The system was not primed for holding back everybody down because of a dumb minority.

2) A dedicated effort to identify the smart kids, direct them to focused high quality schools, encouragement to get involved in serious competitions (mathematical olympiads, but also correspondence seminars) and math clubs.

3) Not so much distracting options to do other interesting things (very unlike the west), so much easier to actually attract and keep the smart kids interested.

The education system is in much worse state now - both 1) and 3) are gone, and 2) is severely affected, mostly by 3).

A Russian friend of mine who was very smart and very good at math clearly comes from what I call the throw your children down a well school of education. It goes like this: “Throw your children down a well. Any child that was not strong enough to climb out on their own was a waste of time anyway.”

Which IMO can also be stated as that saying that goes by "If you want to go faster, travel alone. If you want to go farther, travel together".

There must be a middle ground between setting the bar so high that you will find only the diamonds and setting it so low that almost every rock out there will pass.

The bottom 50 probably don’t benefit from math education anyway.

The USSR turned a largely illiterate Russian population to a literate one very quickly. It achieved one of the fastest mass educational transformations in history. In 1917-1920 it went from inheriting a population with 25% literacy to then having 80-90% literacy by 1929-1939.

Not to mention, Proletarianization of Universities (Rabfaks), which accelerated prep schools attached to universities designed specifically for adult factory workers and peasants who lacked formal secondary education. They also built what were essentially trade school-like institutes to rapidly educate people on medical, pedagogical, and polytechnical studies.

I mean, it also had an academic hardcore side to get star students into positions of power and influence, but all successful societies have that. When we see these very same systems in leading capitalist systems like the US, UK, Germany, Japan, or Korea we applaud them for recognizing and empowering talent. Socialist societies are instead somehow criticized for this.

If anything the Soviets were far more serious about educating everyone than their western peers and one of the reasons they become a world power so quickly.