You might enjoy Beckey Chamber's Galactic Commons series. She does a great job of creating all kinds of interesting characters and exploring them and what makes them unique.

The Sparrow by Mary Doria Russell is very compelling.

And I seconded it below but I'll mention it again - the Bobiverse series is excellent with amazing exploration.

Solar punk as a genre is mainly optimistic. I just read and enjoyed the Monk and Robot novellas, also by Chambers - though I’m not sure they’re ‘scifi’ enough to scratch the itch this thread is about.