This is common in a lot of Seattle neighborhoods, but the custom doesn’t extend beyond the city limits. For the most part it just works, but when I’m in a car with someone not from the city I always need to inform the driver or they just expect right of way. I lived near one of these intersections and personally witnessed two collisions over ten years. Neither were serious. I think these intersections largely work as a custom, save for the people not already accustomed.

The stop signs haven’t changed (on that note we do have lots of traffic calming islands [1]) but we did get the “Idaho” stop in 2020.

[1]: https://overpass-turbo.eu/s/1hHn

The other thing I love about Seattle is that in a lot of places you could park on either side of the street facing either direction. Another one of those weird customs that people just seemed to go with

Seattle can do this with its much smaller neighborhood roads and their roundabouts.

Many other American cities with their much larger (new) suburban roads have cars driving at 30/40 mph in the neighborhood

It's still very common outside of the cores of highly urbanized neighborhoods. I generally like it, but sometimes the visibility isn't as well-maintained as it should be.

Portland has some neighborhoods like this with uncontrolled intersections. They also allow cars to park all the way up to the curb, so it becomes a game of go and pray since you often can't see cross-traffic until you have already entered the intersection.