How would the universe be different if the speed of light were faster, perhaps much faster?
Probably magnetic fields are weaker, or electric fields are stronger. Other subatomic effects probably wreak havoc compared to the current universe. (The "tuning" theorists might say the speed of light is exactly the right speed for intelligent life to observe it and ponder it.)
Inspiration is hard science fiction in an alternate universe in which high speed travel around (say) the galaxy is possible without having to invoke machinations such as hyperspeed or wormholes, or to worry about time dilation.
(Alternatively, the characters could just live longer.)