I think there's plenty of character focused Sci-fi, I'd just say the difference is that it's more of a 50/50 split of character driven and thematically driven. Like Dune is probably good example where it's core is the themes, the critique of imperialism, prophecies, a white savior,, and a very strong ecological focus, etc. Characters can tend to be more secondary to the themes it's trying to convey which is common as scifi is often used a way to critique and comment current society or the path society could be heading down. Where as - while there are exceptions - fantasy tends to lean more towards pure escapism with some vague or more general social themes.

A few people have already brought up some good recommendations, Urusla LeGuin is an excellent choice. She wrote both scifi and fantasy with fantastically fleshed our characters and their journeys that also happened to tie in with some larger ideas.

A few of my own recommendations would be the Metro Trilogy by Dmitry Glukhovsky. It's post apocalyptic and pretty bleak as far as the world goes but it's all character driven. The first and third books follow Artyom, initially a very sheltered young man who dreams of the outside world but knows nothing about it. The first book is essentially his growth as a person, learning about the beauty and horror in equal measure of life. The third book jumps ahead several years and is similarly a character driven story but acts as a deconstruction of the post journey hero. Once the "grand quest" for the hero has been completed, what's left? It explores a lot more by in terms of his character story its much darker with hints of optimism but is similarly entirely driven but his character and experiences.

By the same author is Futu.re, which explores a world where a vaccine has been developed against aging. This leads to number of unintended consequences such as overpopulation, increasing wealth disparity, conflict with religion, purpose, and the like. To combat over population a law has been put in place that if a couple wishes to have a child, one of the parents must give up their immortality to attempt to keep the population stable. However it's a not a flawless system and so to enforce the law, a paramilitary group is formed that forces both parents to give up their immortality or face immediate death. The story follows a member of this paramilitary group as he wanders aimlessly through life and is becoming increasingly disillusioned with the world he lives in. While there are grander events unfolding around him, he himself doesn't really play a part in them as the story is more personally focused on his own life and struggles.

Other good character driven stories would be On the Beach by Nevil Shute that is entirely driven by characters and emotion, there isn't really an "overarching" story more just a gut wrenching portrayal of people living the final months of their lives.