Yeah I've only read The Dispossessed and a few short stories so I might have a tilted view of her bibliography.

I've tried to get into Ian Banks. One feeling I get is that there's two kinds of optimist sci fi. Technology magically solves our problems - or technology can be both force for good and bad, let's use it for good. I have a feeling that Ian M Banks writes the former but I'm probably wrong here?

There can still be interesting conflict even if the bigger problems have been solved. Dispossessed is one good example I think. The conflict is partially about flaws inherent in the "better" society that they created.

And in Star Trek and to some degree in "The long way to a small angry planet" the conflict is between the larger society and the hold outs.