I'm surprised we haven't seen more hard sci-fi in the jovian or cronian systems. While constant 1g acceleration drives open the whole solar system to the ~month travel time that benefits stories, much more realistic accelerations (or limited fuel) can still manage the same within those systems.
If an entire Sci-fi continuity were limited to just Sol and Alpha Centauri, this by itself would constitute an inexhaustible number of potential settings. In addition to planets, moons, asteroids, dwarf planets, Oort cloud and Kuiper belt class objects, there could also be space stations numbering in the tens of millions. Such a setting could use known physics, yet be incredibly vast. The Expanse is going in this direction, but doesn't go that far, and doesn't stick to known physics. (Though it remains closer to it than almost all Sci-fi continuities out there.)