Why are you fist-raping all of my team mates?

I never play ranked, i have mastery 7 with two champs, and only barely. it seemed for a while like the only games i would win were ones where my teammates hard carried me. luckily i had some nice fellows tell me about op.gg, and it doesn't seem random to me when i look at this. i don't get unlucky to sometimes get into a high level matchup, it is consistent. this tells me that there is indeed some algorithm being put to use, and it's unfailingly throwing a below average player on teams that shouldn't have to struggle explaining shit to me when they've put in the time and effort to get past the newbs. stop punishing them with my existence.

this a breakdown of my fellow players' levels for my last 14 SR games:

team:

master: 0 diamond: 5 platinum: 10 gold: 21 silver: 12 bronze: 0 unranked: 22 (14 are me)

enemy:

master: 1 diamond: 8 platinum: 21 gold: 24 silver: 8 bronze: 1 unranked: 7

unfortunately that's as far back as i can see, i left out the aram. my record in these 14 SR games is 4-10. my teams do not deserve to have to try carrying a casual player who has never studied the game or has never really practiced hard with any single champ. i don't expect anything to change, i just want to know why matching-making is constantly fucking over dedicated players with someone like me who is far below their skill level.