Everything needs to be replicated for that stuff, or different clients see different things. Plenty of games DO this, so yes, a game trusting clients is a bug

Everything needs to be replicated for that stuff, or different clients see different things. Plenty of games DO this, so yes, a game trusting clients is a bug IMO. Yes, WoW doesn't do all the movement serverside, cause it can be expensive. But even WoW does checks for "are you moving faster then you should be".