Rio IS super dangerous. Literally all of my wife’s friends have been robbed. My wife had a piece of glass put to her neck (in the worst of 5 times she was robbed or attempted to be robbed). One friend was punched in the face/robbed while sitting in her car in broad daylight stopped in heavy traffic in downtown Rio because she left her window open. Another friend was involved with the pharmacy robbery in botafogo a few months ago, dragged by her hair and told she would die. I myself was trapped in a grocery store for an hour while a shootout happened across the street. I could go on....
But still, that’s for people who live there. Be smart and I highly doubt anything bad will happen to you just on a statistical basis. I always recommend people should visit Rio because IMO there is no better beach in the world than Ipanema.