Up through the 60s, early 70s there were white street gangs similar to the black gangs, GDs, Crips, Bloods, etc. today. Large ones. Italians, Irish, Jewish, even Germans had their own. Very prevalent. You know how they ended? Jobs. Specifically well paying union jobs, factories, city unions controlled by their own people (Irish, Italian), Teamsters, AFL-CIO, United Auto Workers, etc. That's what ended white gangs.
The same can end Black gangs. White folks don't want to do that and we have Black politicians who have sold out. Almost all the great paying union jobs ended as blacks needed them in the '70s and those jobs are in China and Mexico among white areas in America.
Also, whenever Blacks tried to end gang wars, the local police and or the FBI sabotaged it. LA had a major gang truce after the '92 riots. Good right? The cops stopped it by manufacturing beefs.
There are also too many success stories of ex gang members doing big things to write them all off as a collective. There is no structure in place to give the masses of gang members a road out.