https://www.google.com/maps/@38.5513462,-121.7200079,3a,75y,...
As a driver, there's 2 places I need to watch for pedestrians: just before I get into the roundabout, and right at the exit. And the place I need to watch for is the width of a lane of traffic that's directly in front of me. Compared to a 4-way stop. Now there's nearly 180 degrees I need to look: pedestrians crossing the street directly in front of you (so directly left and right), pedestrians crossing the direction you're going to, and the 3 other cars that are stopped at the lights trying to figure out whose turn it really is, since only one person can go because pedestrians are blocking. And then when someone starts going someone inevitably goes into the intersection even though it's not their turn. And bikes/pedestrians not even stopping and looking before going into the intersection. 4-way stops are a complete cluster when there's heavy pedestrian traffic and even a moderate amount of car traffic.