The point of the commentary isn't cryofreezing or the eugenics/handwaved-backstory. Those are a few minute intro just creating the setting and don't make sense nor do they have anything to do with the rest of the plot.

The fun in idiocy is the "isnt this dumb!" take on a bunch of society that is one big dumb step worse than current life but certainly recognizable.

Everything turned into advertising. Costco expanding into everything. Brainless tv and the related celebrities (that people love for the gimmick but don't give a shit about as people). Health care that only supports a diagnosis by matching to a few kid-friendly tiles. Politics as professional wrestling, nepotism, incompetence, and overpromising. For a related laugh, go look at one of the online quizzes from 2016 about "which of these ten quotes are from a real presidential candidate and which are from president comacho".

Idiocracy is a fun, silly satire that is nearly a cartoon, from a bunch of folks who made a bunch of successful social commentary cartoons. It very much isn't a eugenics story - if Mike judge were actually writing that as the intent I think it would be dark and with a vicious ruling class.