I feel like the core idea of sci-fi is - imagine the world, but with some specific thing different. What would the consequences be? Le guin does it with social

I feel like the core idea of sci-fi is - imagine the world, but with some specific thing different. What would the consequences be? Le guin does it with social issues. Someone like Greg Egan does it with laws of physics. The formula is both oddly similar yet totally different. P.s. i'm not sure i would consider Clarke exactly a contemporary of Le Guin. They certainly heavily overlap, but i think Clarke kind of belongs to the previous generation - at least stylistically wise.