> ... but whenever IMO is brought up, a caveat should be put out: medals are awarded to 50% of the participants (high school students), with 1:2:3 ratio between gold, silver and bronze. That puts all gold and silver medalists among the top 25% of the participants.

yes, it is true, but getting to the country specific team is itself an arduous journey, and involves brutal winnowing every step of the way f.e. regional math-olympiad, and then national math-olympiad etc.

this is then followed by further trainings specifically meant for this elite bunch, and maybe further eliminations etc.

suffice it to say, that qualifying to be in a country specific team is imho a big deal. getting a gold/silver from amongst them is just plain awesome !