It's difficult to put a numerical value on a concept like wealth in a post-scarcity society but a thought experiment could work: would you like to have Elon Musk levels of wealth today (while living in today's level of "total global absolute wealth") or live in a world where you can have your own starship, live essentially forever, and have essentially zero constraints on the amount of matter and energy (and their form) you'd conceivably want to use?
Clearly something like The Culture is richer in material wealth (in terms of goods and services and knowledge available), even if it's difficult to put it into pure numerical terms, just as the world we live in now is "richer" than the world we live in three thousand years ago.
