Based (how closely ?) on the 1971 black humour science fiction novel "The Futurological Congress" by Stanisław Lem !

(For those that would not know, he coined the term "robot" from the slavic root "work".)

Are you sure? Wikipedia says the word was coined by Karel Capek:

https://wikiless.org/wiki/Karel_%C4%8Capek?lang=en

Oh damn. My bad - it's funny, I even though to myself : «he would have been quite young, wouldn't he ?»

wow, not many people have seen this movie. 100%.

I'd never heard of it, but definitely going to check it out now. A lot has happened in the ten years since it was created.