My understanding is that they are much less generous on average compared to U.S.

E.g. for now I have the most premium card offered by my bank (50€/mo), and it gets me extra product insurance, rental car insurance, travel insurance, free lounge access, and some other things like that, but no cashback or similar.

I think some premium cards do offer cashback nowadays, but they are in the minority. Some cards also offer airline reward points. My experience is limited to Finland, though.

US are not generous either. Merchant increase prices by 5% to cover costs, you get 2.5% cashback and visa/your bank pockets the other 2.5% you're paying.