Lyon and
Saint-Étienne, both towns being roughly 40 miles apart, that's nothing. Not even an hour distance by driving.
Of course, some would burn me alive as a heretic for saying it, because of their local soccer teams rivalry, but who cares? I surely don't.
There's also historically been something like a social class divide locally. Saint-Étienne is supposed to be a manufacturing, "blue collar", rust-belt-like town, whereas Lyon is quite larger and traditionally better off, with a significant bourgeois and entrepreneur community.
But that's only old history. You wouldn't perceive so much divide between the 2 nowadays.
In fact, the worst is their stupid professional soccer teams lol.