Why let smurfs play in bronze elo?

Here I am, trying to rank up, my team is still new to the game trying to climb up the ranks. I'm a lowly bronze/silver player. I get it, i'm bad. But here's the funny thing. Riot, how do y'all expect any of us new-ish players to climb if you allow smurfs, boosters, and toxic people to play ranked. My question to you all as a company, to let a "smurf" play in bronze and silver, is it ethical to let fake bronze/silver/gold players play ranked if their MMR is godly in their elo... Like, its almost not even worth playing the ranked system if you let a diamond smurf playing a champion like Lee Sin, which is one of the highest skill-based champs to even be mastered in this ELO, carry the hell out of his team or team mate because "his/her friend wants to play higher elo games". I'm sure you know that at a humanistic approach, there is no such thing as a prodigy that barely started playing league. So all i ask of you is, how can you all ensure that higher elo players won't be able to play low ranking games if their MMR is way above the average MMR from a regular bronze/silver/gold player in the future? Will it ever change or not. regardless I'll still play the game, it's just a matter of improving the gaming community for everyone trying to climb. I get it, its not supposed to be easy and its a competitive game, but whats the point of playing ranked if you let people like this play low ranking games. Please no negative feedback.