People don't want to play duelists in ranked because they're easy. They want to play them because they tend to have very selfish kits (heals, get of jail free cards, movement abilities, damaging utility, etc.)
actually it's not. heard many pros that duelist it's very fun and not that hard gameplay, especially because you're team always try to set up you well and you always has chances to do your job easily even if you're not main character in some games