The elo question

I was watching a video of league of legend when the dude said something about smurfing from silver 4 to plat 5 and he told something that he could be placed as a silver with plat talking about mmr inflating . So i came in a conclusion that if you technically perform well you AKA having a super good KDA will get placed with higher elo . So if you technically try to win with hero who doesnt need KDA to win and drastically put effort to feed you can surely reduce the amount of mmr you get when you win from a stomping one where you get a insane KDA . So this mean you need to play top lane with champion like singed , teemo , tryndamere and only focus on pushing the objective , no matter how much you die and just for info im not pretty sure how its work and this post is not a joke, im just saying wht i thought and want to know if it would be truth in some point because if yes you could actually change your playstyle and actually grind mmr in some point and improve the statut of your elo and create quality time in some point .