One of the big themes in the series is how people find meaning in their lives given that they basically want for nothing. When you can have any material possession created for you on demand, what do you do with yourself?

For example, in The Player of Games, Gurgeh devotes his life to games of strategy, and Yay to orbital architecture. Neither character needs to work for a living, so why bother working at all?

IMO, there are much better novels about this subject not involving any techno-magic. Lem's Return from the Stars is an excellent work that explores this very question, and unlike Culture novels, it's down-to-earth and fully self-aware. Hard to explain what that means. Lem realized that the very notion of "meaning" will change in the future.

Many works by Strugackiy brothers also deal with this question.

I realize these writers belong to preceding generations of SF, but their works are still very much relevant and (IMO) far more plausible than futures of Vinge and Banks.

To answer the last question: to define themselves as more than average by joining a community of practice. It is a society where what you do is considerably more distinctive than what you have and where you come from, which is likely to seem strange to us.