Why Riot needs to seriously revamp their matchmaking/ranked system

I get that my rank is Silver, but please explain this matchmaking? I have a Diamond Zoe mid (who is losing VERY HARD to another silver player), 3 players who didn't even play ranked last season (Yi doesn't even have Smite). Somehow, I lose over 20 LP for this, and I understand that this should be 'weighted out over time', but over the course of the past 4 months I feel 4/10 of my games has some similar issue (AFKs, players who shouldn't be in ranked, boosted accounts, etc.).

Is it too hard to ask, considering every mid season and off season we have a large patch that substantially changes the game, to revamp Riot's ranked system, which hasn't been changed in over 3 years (unless you count the free win after losing your series as a 'substantial update'). I'm fine with LP ONLY being gained/lost through wins (which is a pretty archaic system), but a system can easily evaluate the quality of a game, and adjust LP accordingly (OK your Jungler forgot to get Smite, you only lose 1/2 the LP instead of over 20).

Oh and attached is an image of my last game and my last straw with this terrible ranked system. If Riot does one thing, please consider evaluating the QUALITY OF THE GAMES in comparison to how LP is gained/lost instead of the current archaic system, where winning and losing is the only criteria.

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