In Seattle all unmarked intersections are considered pedestrian right-of-ways, by law. There have been campaigns to promote this. Ten to twenty years ago it was not uncommon for pedestrians to throw tantrums and shame drivers for not stopping them, usually in Fremont and Capitol Hill. That may explain some of the behavior; possibly the drivers you encountered were native Seattlites with intersection PTSD.

But I generally agree with you. it’s a often egregious and can be extremely dangerous for both the pedestrian and other vehicles when a lone driver stops unexpectedly on a >2 lane road.

In some states, you can and will be ticketed if you don't stop whenever someone steps off the curb. I seem to remember hearing or reading that is the case in Massachusetts, so you may see drivers from out of state being very cautious even elsewhere.

Also, the other day, I was making a left from a one-way street, from the left side of it, and someone tried to drive around me on the shoulder to the left, because they were unaware I was waiting for a jogger pushing a stroller to cross in front of me.

I almost got run over today on Capitol Hill because of this. A driver in one direction was so insistent that I cross in front of them that I failed to be sufficiently attentive about the other direction and almost got hit.