I'm known for my worldbuilding at this point, but I must admit: if I were asked to choose my favorite element of storytelling, I would have to choose character.
World is something I really enjoy, and the better done it is the happier I am, typically. However, if I find myself reading a book where the world is terrific and the character doesn't make me care, it's not enough. I'm quite serious. Recently I abandoned a very famous book, one famous in particular for its worldbuilding, and one everyone told me I should read, because though the worldbuilding was masterful, the character couldn't make me care.
Characters have emotions. They have goals, and they have fears. Those are the elements that keep me reading.
Some of you will already be anticipating what I'm going to say next.
When worldbuilding is done well, it seeps into character. To my mind, any character who has grown up in a world will have judgments informed by the structure of that world. Their internalized goals will be appropriate to that world, even if they struggle with them. Their fears will also be rooted in the world, for what do they have to fear but what exists in their own world?
The character's emotions will be emotions we recognize - what you might be tempted to call universal emotions - but the more sophisticated the emotion, the more culturally informed it will be. Everybody will fear a hungry bear. But everyone will probably also fear loss of reputation on some level, and the way you maintain your reputation in one world versus another will be vastly different.
The commonality of feeling brings us together with a character in spite of the world's differences. We feel alongside the character, and then our logical understanding of the world tells us whether these emotions make sense in context.
That was one of the things I loved about the characters in N.K. Jemisin's The Hundred Thousand Kingdoms. Every single one of them felt strong emotions, each for different reasons. There were the enslaved gods who were scheming, not arbitrarily, but out of deep anger for their betrayal and enslavement. I could tell that they used their emotions to inform every action they took, even when I didn't understand them. Lady Yeine was sharp, and driven, and full of emotions that grew out of her history - both her personal history and her cultural history as a Darre. You could see how the Darre emotions were expected to be more overtly passionate and the Arameri ones more calculating, but neither was any stronger at its core than the other.
Katniss Everdeen from Suzanne Collins' The Hunger Games is constantly showing emotional reactions that grow out of her world. Bread has an alternate significance because of its scarcity, and informs some of her most important decisions about friendship. The food on the train carrying her to the games isn't just amazing, it's offensive and near-inedible as a result. Yes, she's subject to the Games themselves and there's a life-and-death reason why she has to survive, but everything about her life to that point is a life-and-death struggle, which to me is the more interesting aspect of the book. It's that personal, emotional aspect of the struggle that makes the Games themselves so much more than watching a gory video game.
It's important for characters to have problems, both external and internal. Worldbuilding should make its mark on both kinds. I love working with troubled characters, but I don't want them to be troubled for arbitrary reasons.
My character Nekantor is mentally ill, but it's not just because I want to tell a story about an insane brother. It's also because I'm telling the story of a world that is failing, of a Race that is dying out, and of what kinds of things that slow death will drive its people to do. The fact that Nekantor is obsessed with control, with making sure things stay in their correct locations, and behave in the appropriate manner, and that the First Family is always first, grows directly out of the nature of the world he lives in. It's the larger societal problem faced by the noble caste, played out on a personal scale, with the inbreeding as its cause.
My character Rulii from "Cold Words" is addicted to a substance called molri, and this gives him a lot of trouble, but it's not arbitrary. I didn't mean make him "an addict" the way we consider such things, and in fact the human characters in the story have trouble understanding his addiction because they assume more human reasons why a person might take drugs (for pleasure/escape). Rulii eats molri because it keeps him from shivering in the cold, and because shivering with cold would get him cast out of the Majesty's council, thus keeping him from helping the cause of his oppressed people. The reasoning, and thus the trouble and the emotions associated with it, grow out of the world.
To me, character is more important than worldbuilding. But there's no point in asking whether I would choose one or the other. Because to choose one over the other implies that the two stand separately, and they don't. Character and world should always be inextricable. When they are thoroughly entangled, a focus on character won't mean that your world is obscured - in fact, it will be even more visceral and more sharply defined.
It's something to think about.