This would be useful for a new player who saw gangs up ahead but wasn't close enough to see what threat level they are. With binoculars they can see what threat level they are without getting too close to danger then they can decide whether to pass through or fight them.
It can also be useful for veteran players who see someone at a hardline but they are not close enough to see what org they are so with the binoculars they can find out. If its there own org they know its safe, if its another org they might decide to try another hardline or risk it. But you would be far away enough so they don't see you.