I have never experienced significant harassment, and I am a white male-presenting person in a city that is about 30% white. I've lived in various neighborhoods with varying levels of average income and demography. I would walk and bike basically everywhere that wasn't super hilly. I wonder what is different about your experience, the way you carry yourself, etc. that causes these interactions.
> In my experience, the normal, non-exceptional case, of aggressive behaviour between people on the street is unprovoked harassment by troubled individuals.
My experience is that those people usually know each other in some way. Have you ever taken the time to listen, or is it just too shocking to handle?
The situation you describe would seem to be the exception. Compare to violent crimes like sexual assault or shootings, which are overwhelmingly perpetrated by people who already know the victim prior to the assault.