A lot of people have this idea that they play a lane well, and they actually don't. For example, an adc that farms at lvl18 at 40 minutes without wards into the danger zone or on the enemy side is stupidly common. As in, it happens one out of every two games. This behavior is probably the worst thing a carry can do, as it almost always loses games for their team (but if the carry is doing that to avoid teamfights it's probably already over for that carry's team anyway).
I personally think that these people should be banned from playing those kinds of lane positions (adc) in ranked, but that's not what I'm here to propose as an idea. I think that there should be more information available to players on the client that tells them how they fair in the only two statistics that actually matter: win loss rate and average gold per game given a certain role.