Wet is a significant loss of traction, it's just that wet after a dry spell is even worse.
I'm from the Northeast but happened to be in Seattle on a day when it snowed. Every road was a hill and every hill was full of sideways cars.
People who make fun of greater Seattle for freaking out over snow generally don't understand just how extreme the topography is out here, even downtown and on the highways. It's not Ohio or the Northeast with at most gently rolling hills. It's snow PLUS ridiculously steep terrain.
I would counter that it depends on the kind of tires you are running and anyone selling tires in Cascadia that aren’t wet rated should be locked up for reckless endangerment.
Seattle isn’t that bad in wet pavement, unless it hasn’t rained. Which only happens about four to six times a year but that’s still enough that people should pay attention.