Four way stops are common in lightly trafficked situations where the locals can't justify spending the money on anything but a few stop signs. For instance, the main street through a small town (<2k pop) might have traffic lights and maybe a circle for the one other major road it intersects, but where the two or three roads parallel to that intersect with other town roads, a four way stop makes the most sense. Most of the time a car gets to one, it will be alone. Since neither road is long and neither is expected to have fast cars anyway, a four way stop is the most natural and intuitive option way to sign it.
Four way stops are also common when two country roads of relatively equal weight intersect. There are so many roads like that, so many intersections, that the local government can't possibly afford lights or circles on all of them. If one of the roads is known to get substantially more traffic than the other than a two-way stop is usually used, but if it isn't obvious then a four way stop is the safe default. In these situations, pedestrians aren't a factor at all because the intersection is five miles away from a town and it's farmland on both sides of both roads. Virtually nobody is walking there, not even people walking their dogs (unpaved access roads are better for that anyway.)
I'm not sure why the four way stop "makes the most sense".
In Europe one road (perhaps arbitrarily) would be declared the main road, and the other road gets yield signs, or even just yield road markings (triangles).
If one is obviously a main road then it's a two way. If neither is, then it's a four way. If the intersection is lightly trafficked then there's not any reason not to make it a four way because it won't cause meaningful delays anyway. When a county has several hundred country road intersections that get a few dozen cars or less a day through them, it doesn't make sense to even spend time studying each one. Just throw up some stop signs and consider the matter resolved.
Or do what they do in the UK. For all of these, make them 'mini-roundabouts' which is literally a dot painted on the center of the road. You follow the rules of the roundabout without building one. Works just as efficiently as a four way stop with light traffic - actually more, since you don't need to stop if the intersection is empty.
Or, in the absence of any signage, it'd just be "right before left". Relatively common in the outskirts of cities where there isn't one road that has significantly more traffic than the other one.
No, that’s not the same. On a 4-way stop you have to completely stop. Also how I remember my year in the US (I’m from NL) is that the first to reach the stop has right of way, not the “left” one. But I might be wrong on that last one? Didn’t have a drivers license at the time (but was surprised - and turned off from - 4-way stops).
Four way stops are also common when two country roads of relatively equal weight intersect. There are so many roads like that, so many intersections, that the local government can't possibly afford lights or circles on all of them. If one of the roads is known to get substantially more traffic than the other than a two-way stop is usually used, but if it isn't obvious then a four way stop is the safe default. In these situations, pedestrians aren't a factor at all because the intersection is five miles away from a town and it's farmland on both sides of both roads. Virtually nobody is walking there, not even people walking their dogs (unpaved access roads are better for that anyway.)