I lived for over thirty years in the United States, but mostly stopped biking there. Now I bike everywhere.
I agree with everything you say but you're missing a key point - the active hostility that a significant number of drivers have for bikes.
I biked in Canada for ten years, and drivers there (at the time) were mostly indifferent to bikes.
(And yet I say this, and then I remember that one of Canada's rising bike stars at the time was permanently paralyzed by a driver who had repeated tried to force him off the road before (in his small community) and who had been reported to the police many times for it, and yet suffered no penalty other than a temporary license suspension. This was in the early 80s, and I haven't thought about it in 30 years, but I still feel a rush of rage.)
Now I live in the Netherlands, and cars are actively solicitous of bikes. Let me tell you that the center of Amsterdam has a lot of cobblestone streets with no separation between bikes and cars, not even a line on the street, but (nearly all) the cars treat cyclists as if they are delicate and breakable, which is actually the case.