I've driven in five Canadian provinces, one Territory, Alaska, about 30 other US states, Jamaica, Cuba, Costa Rica, and .... wait for it ... Morocco. Whether it was Interstates around Chicago or freeways in San Francisco~San Jose, and gravel roads with nothing but oncoming tractor-trailers with wobbling logs 40" in diameter stacked on dubious flatbeds at 50 mph (while I was going faster).
I've lived in Minneapolis which I must admit doesn't have terrible traffic, but it can get big-city at the wrong times of day.
And if you operate a motorcycle, you learn pretty quickly that no amount of traffic ... sparse or as dense as can fit bumper to bumper ... is safe from other drivers. I just don't waste perfectly good avoidance reaction time hitting a horn button, whether on the bike or in a car or truck.
I don't know how people are taught to drive these days, from the looks of things pretty poorly I must surmise, but I learned from my father which is what our Nanny State Do-Gooders insist is the wrong way to do it. Can't really argue there as it's obvious to me that there are plenty of people who shouldn't be teaching their kids anything at all, let alone something so important as handling a two ton missile at 80 mph. We had Drivers' Ed in school but I didn't take it. Didn't harm me any, but maybe I am the exception.
Oh, and I've spent perhaps 20,000 hours driving a boat. Legally we had to have "a noise making device" which we decided was a steel frying pan and my axe, both of which were too far away to take my hand off the tiller (15~90 HP, depending) so I would have had to stop the boat to use them. ;-) Later on we upgraded the equipment to a whistle, which was kept packed away inside a waterproof floating container.
And then there's the Private Pilot's license.
Not trying to judge anyone, people have different driving styles and that's fine. There are far worse driving habits. The few times I've used my horn were in parking lots, probably saved a few fender benders there. I understand there's a reason why they are mandatory to pass a safety.