First off most would agree on the drug game the street gangs have that area locked down almost completley except for the mob selling to middle class and upper middle class people who would't go to a gang neighborhood to get their fix.

Second the mutual respect between street gangs and the mob stems from the mob kinda being considered OGs by street gangs who have the glamorized idea of mobsters from the movies. What allows for the respect is that gangs and the mafia are in two different worlds criminally and personally. The gangs have their turf usually in lower income areas where the mafia is not present and doesn't have operations and the mob has their territory,operations and hangouts in more middle and upper class neighborhoods where the street gangs are not present so they never really interact except for in prisons so the idea of a war between gangs and the mob is very unlikely. Also on another note the mob in the U.S doesn't have the large heroin pipelines anymore like in the past so the drug dealing that they do is on a small scale basically the gangs control the drug trade and the mob is into gambling,loansharking,construction,unions and some financial schemes which the gangs are not into, so basically the interaction between the two organizations is on a small scale and they never really step on each others toes because their rackets hardly ever cross paths

Also on your other point both organizations are dangerous but the gangs are defintley more crazy with drive by shootings and killing women and children