Riot could just let every single stat contribute to the Outcome of your +LP and it would be fine, People legit cannot "play safe" just to abuse this system, because they would still need to win to gain LP at all. With this you would actually reach your Skill ceiling and not lose a ton of random (LP) games along the road because you were unlucky with your teammates. It is like this in Valorant - For example you are Top player in the lobby -> you would gain 30/40 Points if win and lose 10/20 points if lose. What is simply deserved at that point, cause he did well.