13 is a mess indeed but 4 is also bad , 7 has a lot of trouble, 12 has crack addicts on the dock menacing passengers, etc..
i’m also born and raised in Paris, and lived there for 40 years, but once you take the subway in other crowded cities ( honk kong, tokyo, shanghai, sf , london, etc) you realize having a subway that smells urine and shit , has technical issues every single days, and simply can’t handle the population flow at all, isn’t « normal ».
We can live with it, the whole society has adapted to it, but i wouldn’t call the situation «fine».