Please realize that 20/19/2 is probably better than 3/1/10
A 20/19/2 person is sticking their neck out to fight and make plays to win the game for the team, and at least they are taking risks.
A 3/1/10 person could be a level 6 Karthus who died once in lane, gets mad and wants to leave the game but can't because he doesn't want to be leaverbustered, so he decides to sit in base ulting every 180 seconds, piggybacking assists and occasional kills from those ults, and doing nothing else.
This is an extreme example, but from my experience, I have met 1 player who has 0-1 deaths in a 40+ minute game who actually did a lot by splitpushing and assisting the team. the other players I have played with that have 0-1 deaths in a 40+ minute game were usually: -too scared to engage and end up piggybacking assists after others have already engaged -attempted KSers who fail at their KS attempts -people who don't know when to time how to go into a fight and help
I'm not even talking about assists vs kills here.
Even f it was 20/1/3
I would say that 20/19/3 is probably more active in the game as a whole and more useful.
20/1/3 sounds like a KSer who sits on the sidelines and does nothing, and waits for the last hit to flash in and ult.