Earlier quoted context omitted.
Since it was a communist country, everyone had the same conditions (crappy), and everyone had the same fricking clothes (only two clothing factories on the whole country), and same teachers (and no private schooling allowed), and we had the same books, and no calculators. And it is clear, if all conditions are equal, still people are not born equal. Some kids are just smarter than others, and some are just dummies, o…
Do you have data or anecdata on the effect of repeating an entire year? In many modern Western schools that'd be frowned upon as punitive and as likely to provoke a "well screw YOU!" response or ingrain "I must really be stupid" mindset.
Edit: Switzerland has a different approach where children are segregated by their ability starting from 7th school year. So you go to Gymnasium, A level, B level, C level.