Whoever said "just cs and don't feed and you'll win" has clearly never played this game before.

All the farm and uptime while alive means nothing when your team's jungler is dead a third of the game while theirs gets infernal drake infernal drake infernal drake baron baron.

So fuck this "just don't feed bro" mentality because it doesn't work. The worst player on your team has more impact than the best player on either because it turns out a 4v5 is harder to win than a 5v6. You need to not just not feed but be able to hard carry minimum 3 blind apes and usually 4 to have any chance of winning in this game. "being carryable" means only as much as hoping you win the coinflip of teammates.

To rephrase, in order for this cs and don't die strategy to have any meaningful impact, everyone has to be on board doing the same, and given that you can only control one champion in the game, that isn't feasible.